Ann. Mo. Bot. Gard., Vol. 2, 1915 Plat 2 } ; Fig. 1 Fig. 2 BRITTON— VEGETATION OF VfO A ] LAND COCKAYNE, i:oston ANNALS OF THE MISSOURI BOTANICAL GARDEN Annals of the Missouri Botanical Garden Volume 1915 AVitli Twenty- seven : P4*ites &n<4* ^.eyenty-nine Figures _ . • * • -. - • • • * • mm • • • * • z • # * Published quarterly by the Board of Trustees of the Missouri Botanical Garden, St. Louis, Mo. Entered as second-class matter at the Post Office at St. Louis, Missouri, under the Act of March 3, 1879. £4088 Annals of th e Missouri Botanical Garden A Q tory of larterly Journal containing Scientific Contribut: Missouri Botanical Garden and the Graduate Lab Henry School of of Washing! Missouri Botanical Garden Editorial Committee George T. Moore Benjamin M. Duggar Information The Annals of the Missouri Botanical Garden appears four times dur- ing the calendar year, February, April, September, and November. Four numbers constitute a volume. Subscription Price Single Numbers $3.00 per volume. 1.00 each. The following agent is authorized to accept foreign subscriptions: William Wesley & Son, 28 Essex Street, Strand, London. • • • jroit G^e • • • STAFF OF THE MISSOURI BOTANICAL GARDEN Director, GEORGE T. MOORE. Benjamin M. Duggar, Physiologist, in charge of Graduate Laboratory. Hermann von Schrenk, Pathologist. Jesse M. Greenman, Curator of the Herbarium Edward A. Burt, Mycologist and Librarian. Alva R. Davis, Research Assistant. C. E. HUTCHINGS, Photographer. Katiierine H. Leigh, Secretary to the Director. BOARD OF TRUSTEES OF THE MISSOURI BOTANICAL GARDEN President, EDWARDS WHITAKER Vice-President, DAVID S. H. SMITH. Edward C. Eliot. George C. Hitchcock. P. Chouteau Maffitt. Edward Malunckrodt, Leonard Matthews. William H. H. Pettus. Philip C. Scanlan. John F. Shepley. EX-OFFICIO MEMBERS: Edmund A. Engler, President of the Academy of Science of St. Louis. James P. Harper, President of the Board of Public Schools of St. Louis. David F. Houston, Chancellor of Washington Uniyersity Henry W. Kiel, Mayor of the City of St. Louis. Daniel S. Tuttle, Bishop of the Diocese of Missouri A. D. Cunningham, Secretary. TABLE OF CONTENTS PAGE The Twenty-fifth Anniversary Celebra- tion 1- 32 N. Wille 59-108 The Vegetation of Mona Island N. L. Britton 33- 58 The Flora of Norway and its Immigra- tion The Phylogenetic Taxonomy of Flower- ing Plants C. E. Bessey 109-164 The Botanical Garden of Oaxaca C. Conzatti 165-174 The Origin of Monocotyledony J. M. Coulter 175-183 The History and Functions of Botanic Gardens A. W. Hill 185-240 Recent Investigations on the Proto- plasm of Plant Cells and its Colloidal Properties F. Czapek 241-252 The Experimental Modification of Germ- Plasm D. T. MacDougal 253-274 The Relations between Scientific Botany and Phytopathology 0. Appel 275-285 The Law of Temperature Connected with the Distribution of the Marine Algae W. A. Setchell 287-305 Phytopathology in the Tropics Johanna Westerdijk 307-313 Phylogeny and Relationships in the Ascomycetes G. F. Atkinson 315-376 A Conspectus of Bacterial Diseases of Plants E. F. Smith 377-401 TABLE OF CONTENTS PAGE Rhizoctonia Crocorum (Pers.) DC. and R. Solani Kiilm (Corticium vagum B. & C.) with Notes on Other Species .B. M. Duggar 403-458 Some Relations of Plants to Distilled Water and Certain Dilute Toxic So- lutions M. C. Merrill 459-506 Electrolytic Determination of Exosmo- sis from the Roots of Plants sub- jected to the Action of Various Agents M. C. Merrill 507-572 Monograph of the North and Central American Species of the Genus Se- necio— Part II J. M. Greenman 573-626 The Thelephoraceae of North America. IV E. A. Burt 627-658 Toxicity of Galactose for Certain of the Higher Plants Lewis Knudson 659-666 Comparative Studies in the Polypora- ceae L. 0. Overholts 667-730 The Thelephoraceae of North America. V E. A. Burt 731-770 Enzyme Action in the Marine Algae A. R. Davis 771-836 General Index to Volume II 837-841 Annals of the Missouri Botanical Garden Anniversary Proceedings Vol. g FEBRUARY-APRIL, 1915 NOS. 1 AND & THE TWENTY-FIFTH ANNIVERSARY CELEBRATION The twenty-fifth anniversary of the organization of the Board of Trustees of the Missouri Botanical Garden was cele- brated at the Garden on October 15 and 16, 1914. A list of the American and foreign scientists in attendance, the com- plete program of the anniversary exercises, the banquet pro- ceedings, and the papers presented at the scientific meetings will be found respectively on pages 1-3, 4-5, 6-27, and 29-401. Delegates and Visiting Scientists MR. S. ALEXANDER Detroit, Michigan DR. FRANK M. ANDREWS Indiana University, Bloomington, Indiana DR. O. APPEL Kaiserlichen Biologischen Anstalt, Berlin, Germany DR. CHARLES O. APPLEMAN Maryland Agricultural Experiment Station, College Park, Maryland DR. J. C. ARTHUR Purdue University, Lafayette, Indi- ana DR. GEORGE F. ATKINSON Cornell University, Ithaca, New York DR. C. B. ATWELL Northwestern University, Evanston, Illinois Ann. Mo. Bot. Gard., Vol. 2, 1915 DR. I. W. BAILEY Bussey Institution, Jamaica Plain, Massachusetts DR. H. M. BENEDICT University of Cincinnati, Cincin- nati, Ohio DR. CHARLES E. BESSEY University of Nebraska, Lincoln, Nebraska PROF. MABEL BISHOP Rockford College, Rockford, Illinois DR. CAROLINE A. BLACK New Hampshire College, Durham, New Hampshire DR. FREDERICK H. BLODGETT Texas Agricultural Experiment Sta- tion, College Station, Texas DR. N. L. BRITTON New York Botanical Garden, New York City (1) [Vol. 2 2 ANNALS OF THE MISSOURI BOTANICAL GARDEN MRS. E. G. BRITTON New York Botanical York City Garden, New DR. GEORGE D. FULLER University of Chicago, Chicago, 111 inois DR. SEVERANCE BURRAGE Indianapolis, Indiana DR. T. J. BURRILL University of Illinois, Urbana, Ill- inois DR. OTIS W. CALDWELL University of Chicago, Chicago, Ill- inois DR. H. S. CONARD Grinnell College, Grinnell, Iowa DR. JOHN G. COULTER Bloomington, Illinois DR. JOHN M. COULTER University of Chicago, Chicago, Ill- inois DR. STANLEY COULTER Purdue University, Lafayette, Ind- iana DR. HENRY C. COWLBS University of Chicago, Chicago, Ill- inois REV. JOHN DAVIS Hannibal, Missouri DR. R. H. DENNISTON University of Wisconsin, Madison, Wisconsin PROF. H. B. DORNER University of Illinois, Urbana, Ill- inois DR. FREDERICK DUNLAP University of Missouri, Columbia, Missouri DR. E. J. DURAND University of Missouri, Columbia, Missouri DR. R. A. EMERSON Cornell University, Ithaca, New York PROF. A. T. ERWIN State College, Ames, Iowa DR. WILLIAM G. FARLOW Harvard University, Cambridge, Massachusetts DR. MARGARET C. FERGUSON Wellesley College, Wellesley, Massa- chusetts DR. F. D. FROMME Indiana Agricultural Experiment Station, Lafayette, Indiana PROF. P. L. GAINEY Kansas Agricultural hattan, Kansas College, Man- Eng- Ken- Gen Ber DR. REGINALD R. GATES L'niversity of London, London, land PROF. A. H. GILBERT St ate University, Lexington, tueky DR. RICHARD GOLDSCHMIDT Head, Department of Animal etics, Kaiser Wilhelm Institut, lin, Germany DR. ROBERT F. GRIGGS Ohio State University, Columbus, Ohio DR. H. A. HARDING University of Illinois, Urbana, Ill- inois DR. J. ARTHUR HARRIS Station for Experimental Evolution, Cold Spring Harbor, New York DR. L. H. HARVEY State Normal School, Kalamazoo, Michigan DR. ANSEL F. HEMENWAY Transylvania University, Lexington, Kentucky DR. HENRI HUS University of Michigan, Ann Arbor, Michigan DR. F. D. KERN Pennsylvania State College, State College, Pennsylvania I)R. J. S. KINGSLEY University of Illinois. Urbana, Ill- inois DR. J. E. KIRKWOOD University of Montana, Missoula, Montana DR. LEWIS KNUDSON Cornell University, Ithaca, New York DR. EDWARD KREMIRS University of Wisconsin, Madison, Wisconsin DR. W. J. G. LAM) University of Chicago, Chicago, Ill- inois DR. GEORGE LEFEVRE University of Missouri, Columbia, Missouri 1915] ANNIVERSARY CELEBRATION VISITING SCIENTISTS 3 DR. MICHAEL LEVINE Commercial High School, New York City DR. I. F. LEWIS University of Missouri, Columbia, Missouri DR. D. T. MACDOUGAL Carnegie Institution, Tucson, Ari- zona DR. J. N. MARTIN Iowa State College, Ames, Iowa MR. FRED A. MILLER Indianapolis, Indiana DR. C. F. MILLSPAUGH Field Museum of Natural History, Chicago, Illinois DR. D. M. MOTTIER Indiana University, Indiana Bloomington, DR. AVEN NELSON University of Wyoming, Laramie, Wyoming DR. W. A. NOYES University of Illinois, Urbana, Ill- inois DR. LULA PACE Baylor University, Waco, Texas DR. L. H. PAMMEL Iowa State College, Ames, Iowa MR. GEORGE L. PELTIER University of Illinois, Urbana, Ill- inois DR. WANDA MAY PFEIFFER University of Chicago, Chicago, Ill- inois DR. A. J. PIETERS University of Michigan, Ann Arbor, Michigan DR. C. V. PIPER Department of Agriculture, Wash- ington, D. C. DR. RAYMOND J. POOL University of Nebraska, Lincoln, Ne- braska PROF. J. L. PRICER State Normal School, Normal, Ill- inois DR. M. J. PRUCHA University of Illinois, Urbana, Ill- inois DR. FRANCIS RAMALEY University of Colorado, Boulder, Colorado DR. GEORGE M. REED University of Missouri, Columbia, Missouri DR. W. A. SETCHELL University of California, Berkeley, California DR. BOHUMIL SHIMEK Iowa State University, Iowa City, Iowa DR. ALEXANDER SMITH Columbia University, New York City DR. ERWIN F. SMITH Department of Agriculture, Wash- ington, D. C. DR. LAETITIA M. SNOW Wellesley College, Wellesley, Massa- chusetts DR. HERMAN A. SPOEHR Desert Laboratory, Tucson, Arizona PROF. W. C. STEVENS University of Kansas, Lawrence, Kansas DR. S. M. TRACY Department of Agriculture, Biloxi, Mississippi DR. E. N. TRANSEAU State Normal School, Charleston, Ill- inois MR. A. G. VESTAL University of Colorado, Boulder, Colorado DR. ELDA R. WALKER University of Nebraska, Lincoln, Ne- braska DR. HENRY B. WARD University of Illinois, Urbana, Ill- inois DR. JOHANNA WESTERDIJK Phytopathological Laboratory, Am- sterdam, Holland DR. KARL M. WIEGAXD Cornell University, Ithaca, New York DR. E. MEAD WILCOX University of Nebraska, Lincoln, Ne- braska DR. N. WILLE University of Christiania, Chris- tiania, Norway DR. WILLIAM L. WOODBURN Northwestern University, Evanston, Illinois DR. R. B. WYLIE State University, Iowa City, Iowa 4 ANNALS OP THE MISSOURI BOTANICAL GARDEN [Vol. 2 Program Thursday, October 15 10: 30 A.M. AUTOMOBILE RIDE THROUGH THE CITY FOR DELEGATES AND VISITING SCIENTISTS 1 : 00 P. M. LUNCH AT THE GARDEN 2:00 P.M. FIRST SCIENTIFIC PROGRAM (Graduate Lecture Room) Address of Welcome - Director George T. Moore The Vegetation of Mona Island director-in-chief n. l. britton New York Botanical Garden, Bronx Park, New York The Flora of Norway and Its Immigration PROFESSOR N. WILLE University of Christiania, Christiania, Norway The Phylogenetic Taxonomy of the Flowering Plants professor charles e. bessey University of Nebraska, Lincoln, Nebraska The Botanical Garden of Oaxaca DIRECTOR CASSIANO OONZATTI Botanical Garden of the State of Oaxaca, Mexico (Read by Title) The Scientific Significance of the Imperial Botanic Garden of Peter the Great, with Special Reference to the Flora of Asia dr. wladimir i. lipsky Jardin Imperial Botanique de Pierre le Grand, St. Petersburg, Russia (Read by Title) Comparative Carpology of Cruciferae with Vesicular Fruits — Some General Biological and Systematic Conclusions director j. briquet Jardin Botanique de la Ville Geneve, Geneva, Switzerland (Read by Title) The Origin of Monocotyledony professor john m. coulter University of Chicago, Chicago, Illinois The History and Functions of Botanical Gardens assistant director arthur w. hill Royal Botanic Gardens, Kew, England (Read by Title) 8 : 30—1 1 : 30 P. M. RECEPTION. DIRECTOR'S RESIDENCE 1915] ANNIVERSARY CELEBRATION PROGRAM 5 10: 30 A.M. Program (Continued) Thursday, October 16 SPECIAL PERSONALLY CONDUCTED TRIP THROUGH CONSERVATORIES AND GROUNDS OF THE HARDEN GARDEN; LN- HERBARIUM. 12 : 30 P. M. LUNCH AT THE GARDEN 1: 30 P.M. SECOND SCIENTIFIC PROGRAM (Graduate Lecture Room) Recent Investigations on the Protoplasm op Plant Cells and Its Colloidal Properties professor frederick czapek Physiologisches Institut der K. K. Deutschen Universitat, Prag, Austria (Read by Title) Experimental Modification of the Germ-Plasm director d. t. macdougal Department of Botanical Research, Carnegie Institution of Washington, Tucson, Arizona Hormone im Pflanzenreich director hans fitting Botanische Anstalten der Universitat Bonn, Bonn, Germany (Read by Title) The Eelations of Scientific Botany to Phytopathology geheimer regierungsrat dr. o. appel Kaiserlichen Biologischen Anstalt fur Land- und Forsttoirtschaft, Berlin- Dahlem, Germany The Law of Temperature Connected With the Distribution of Marine Algae professor william a. setchell University of California, Berkeley , California Ueber Formbildung und Rhythmik der Pflanzen director georg KLEBS Botanisches Institut Universitat Heidelberg, Heidelberg, Germany (Read by Title) Phytopathology in the Tropics DIRECTOR JOHANNA WESTERDIJK Phytopathological Laboratory, Amsterdam, Holland Phylogeny and Relationships in the Ascomycetes professor george f. atkinson Cornell University, Ithaca, New York The Organization of a Mushroom professor a. h. reginald buller University of Manitoba, Winnipeg, Canada (Read by Title) A Conspectus of Bacterial Diseases in Plants DR. ERWIN F. SMITH Bureau of Plant Industry, U. 8. Department of Agriculture, Washington, D. C. 7 : 30 P. M. TRUSTEES' BANQUET. LIEDERKRANZ CLUB. [Vol. 2 6 ANNALS OF THE MISSOURI BOTANICAL GARDEN Banquet mr. edwards whitaker Toastmastcr Ladies and Gentlemen: This being an epoch in the history of the Missouri Botanical Garden, it was thought that a short biography of its founder and benefactor would be interesting. Henry Shaw was born in Sheffield, England, July 24, 1800. He received his primary education at Thome, a village a few miles distant from his birthplace, and at this early age developed a fondness for flowers and plants. Completing his course at Thorne, he continued his education at Mill Hall, twenty miles distant from London, where he was a student for six years. In 1817 he entered the service of his father, who was a manufacturer and dealer in metal wares, such as andirons, grates, etc. In 1818 his father sailed from England with his family for America, landing in Canada. We are without reliable inform- ation as to the exact place in which he located. The same year, probably in the late fall, he sent his son to the city of New Orleans to familiarize himself with the planting and growing of cotton. The climate of New Orleans did not suit him and the business was not to his liking, and his stay in Louisiana was short. He decided to seek his fortunes else- where, and so took passage on the "Maid of Orleans," and landed at St. Louis, May 3, 1819. With the assistance of his uncle, James Hoole of Sheffield, he started a cutlery and hardware business in a room on the second floor of a building in the business district, which served as warehouse, show-room, office, and dwelling, doing his own cooking and housework, as he was without, and never was blessed with, a better half. His business was successful and uniformly profitable, and, at the age of 39, he had amassed a fortune, as he thought, large enough for any one and sufficient to gratify his taste for botany and the sciences. 1915] ANNIVERSARY CELEBRATION — BANQUET 7 He retired from business in 1840, and took a trip abroad, the first since leaving his native shore. This trip was evi- dently of short duration, as in 1842 he arranged his affairs and sailed a second time for the Old World, remaining three years, traveling extensively and making the acquaintance of botanists and scientists. Holding the English idea that a gentleman of fortune and leisure should maintain a town house and country home, he commenced the erection of his country home on the Garden grounds in 1848, completing it in 1849, and in 1851 built his town house at the corner of Seventh and Locust Streets, the site now occupied by the Mercantile Club. His last trip abroad was in 1851, and in 1858 he commis- sioned Dr. George Engleman of this city, a noted botanist then traveling in Europe, to procure material and information that he thought would be of service to a botanical garden ; and at the suggestion of Sir William J. Hooker, then Director of Kew Gardens, began to prepare a laboratory and erected a museum building, and this was the commencement of Shaw 's, now the Missouri Botanical, Garden. While constructing the garden along the lines suggested by Sir William J. Hooker, he commenced the improvement of a tract of land immediately south of the Garden, now known as Tower Grove Park. In 1857 he had an act of the legisla- ture passed authorizing the city to receive, under certain con- ditions, as a donation this tract for a park. Among them was that the park was to be managed and controlled by a board of park commissioners of his appointment ; secondly, that appro- priations were to be made sufficient to complete it in accord- ance with the plans already adopted ; and the third condition, that an annual appropriation sufficient for its maintenance should be made; and in 1868 he deeded the property to the City. Having in mind the conveying to Trustees of his estate to be administered by them for the benefit of the Garden, and a question having arisen whether such a trust was legal and could be administered in this state, he had an act of the legis- lature passed declaring his intentions, and authorizing him to [Vol. 2 8 ANNALS OF THE MISSOURI BOTANICAL GARDEN transfer his property to trustees and further declaring it lawful. Shortly afterwards, the Supreme Court of the state decided in the case of Chamhers vs. The Mullanphy Belief Fund Bequest, that such trusts were legal and could be admin- istered in this state, thereby removing the doubt entertained by some of the legal profession. In 1866 Mr. Shaw secured the services of Mr. James Gurney from the Royal Botanical Garden in Regents Park, London, who was Head Gardener during Mr. Shaw's lifetime and for several years afterward, and is now Head Gardener Emeritus, and also Superintendent of Tower Grove Park. There is no record of Mr. Shaw ever having had a public opening of the Garden, and a committee of trustees appointed to investigate and report on the date the Garden was estab- lished, decided that the Missouri Botanical Garden began its existence in 1889, upon the organization of the trust declared by Mr. Shaw's will. Mr. Shaw executed his will January 26, 1885, devising his estate, with the exception of a few minor bequests, to a board of trustees of seventeen, the original members of which were designated in the will, and the board thus constituted, ex- clusive of certain ex-officio members, was to be self-perpetu- ating. The five trustees by virtue of the offices they hold were the Mayor of the City of St. Louis, the Chancellor of Washington University, the Episcopal Bishop of the Dio- cese, the President of the Board of Public Schools, and the President of the St. Louis Academy of Science. There were two honorary trustees appointed, Professor Asa Gray of Har- vard University, and Professor Spencer F. Bair'd of the Smithsonian Institution. Before the death of Mr. Shaw, on August 25, 1889, and the probating of his will, on September 17, both of the honorary trustees had passed away as well as two of the active members of the Board. The remaining trustees met October 14, 1889, at Mr. Shaw late residence, Seventh and Locust Streets, and effected an organization of the Board, electing Mr. Rufus J. Lackland President, Mr. Henry Hitchcock Vice-President, Mr. A. D. 1915] ANNIVERSARY CELEBRATION BANQUET 9 Cunningham, Secretary and Treasurer, and appointing Pro- fessor William Trelease Director. Immediately thereafter, by-laws were adopted and com- mittees appointed so that the estate could be efficiently managed. There were four committees — the Garden Com- mittee, the Auditing Committee, the Lands Committee, and the Ways and Means Committee — the President of the Board being ex-officio member of all committees. All actions of the committees require the approval of the Board before becom- ing operative. There have been three Presidents, three Vice-Presidents, one Secretary and Treasurer, and two Directors of the Garden since the organization of the Board. Of the original trustees named in the will but one survives, Mr. William H. H. Pettus, whose feeble health prevents his being with us this evening. There are but two salaried officers connected with the estate, the Secretary and Treasurer, and the Director, the trustees serving without compensation. And I wish here to correct an impression prevailing among many that this estate is exempt from taxation. That is erroneous. With the exception of the Garden grounds proper, the estate pays taxes the same as any citizen, and I may add that this item consumes about one-fourth of the gross income, the remainder being used for the maintenance of the Garden and other objects of the trust. Mr. Shaw was a man of independent thought and action, and while devising his estate to trustees, he at the same time appointed the public administrator of the City of St. Louis the executor of his will. Among provisions of the will was an annual appropriation for a flower sermon to be preached at such church and by such minister as the Bishop of the Diocese may select; an annual banquet for florists and gardeners in and about St. Louis, at which the Director of the Garden was to preside ; a banquet for the trustees and the guests they may invite — literary and scientific men and friends and patrons of the natural sciences. Another provision of the will was that his residence at Seventh and Locust Streets was to be taken down and rebuilt [Vol. 2 10 ANNALS UF THE MISSOURI BOTANICAL GARDEN upon the Garden grounds. It also provided that the Garden should be open to the public every day in the week, excluding holidays and Sundays with the exception of the first Sunday of June and September in each year, when the Garden should be open from 2 : 00 p. m. to sundown. This latter provision was literally carried out until the spring of 1912, when the Board thought the best interests of the Garden would be promoted by adding additional Sundays, and, having legal advice that there was no objection to their so doing, it was opened from April 1 to December 1, from 2 : 00 o 'clock until sundown. This action proved to have been wise, as the attendance at the Garden increased threefold. Such, briefly, ladies and gentlemen, were the objects and the accomplishments in the life of Henry Shaw, a man of whom any City, State or Nation might well be proud, and I request that this assemblage rise and drink with me, in silence, to the memory of Henry Shaw. [This toast was then drunk by those assembled.] The Toastmaster then presented as follows the apologies of the Hon. Henry W. Kiel, Mayor of the City of St. Louis, who had been expected to respond to a toast: Mr. Shaw in his wisdom appointed as one of the Trustees the highest official of the City of St. Louis. He was with us a short time this evening and was compelled to leave, owing to a previous engagement that he thought it would be impos- sible to break, and I have promised him to make his apologies for not remaining. In introducing the next speaker of the evening, Dr. Johanna Westerdijk, Director of the Phytopathological Laboratory, Amsterdam, Holland, the Toast- master spoke as follows: "VVe are complimented by the presence this evening of a lady from a foreign shore, whose achievements have given her a high position in the botanical world. It is my privilege to introduce Dr. Johanna "Westerdijk, of Amsterdam. DR. JOHANNA WESTERDIJK Mr. Chairman, Ladies and Gentlemen: This is a delightful day, but I am sorry that not our great Holland botanist is in 1915] ANNIVERSARY CELEBRATION BANQUET 11 our midst. He would be so much more able to express his feelings for America and for the Missouri Botanical Garden, which I know he loves so well. But since he is not here, I think it is a great honor for me to express my feelings, and I know that these feelings are the feelings of all the Dutch botanists, who all love botanical gardens, from the day of Boerhaave up to recent times. Mr. Chairman and Trustees, and Mr. Director Moore of the Botanical Garden, I thank you in the name of Holland for the delightful day, for the splendid reception I have had here; and if I may express myself in a bit of your American slang at a most solemn banquet, I thank you for the most jolly time I have had in this most delightful bunch of interesting American botanists. Geheimer Regierungsrat Dr. 0. Appel, of the Kaiserlichen Biologiachen Anstalt, Berlin-Dahlem, Germany, was next called upon by the Toastmaster in the following words: We have been favored by the presence of a number of for- eigners, among them a neighbor of Dr. Westerdijk, and I trust that, being in the Liederkranz Club, he will feel sufficiently at home to give us his impressions of our country, through which he has travelled extensively. I take pleasure in intro- ducing Dr. 0. Appel, of Berlin. DR. 0. APPEL Ladies and Gentlemen: If I should speak to you of my botanical or phytopathological work, I could use your lan- guage; but to express my feelings I must use my mother tongue, the German language ! Sie haben zu dem Tage, den Sie heute festlich begehen, audi eine Anzahl europaischer Fachgenossen eingeladen und die Beteiligung von einer groszen Anzahl erwartet. Die Griinde, die die meisten Ihrer europaischen Gaste am Erscheinen ver- hindert haben, sind Ihnen bekannt und werden wohl von Ihnen alien bedauert. Dasz eine grosze Anzahl hervorragender Vertreter des Auslandes hier erwartet wurde, hat seine Berechtigung, denn in den Jahren seines Bestehens hat der Botanische Garten von [Vol. 2 12 ANNALS OF THE MISSOURI BOTANICAL GARDEN St. Louis sich wiirdig in die Reihe der groszeren derartigen Institute eingegliedert, und trotz der groszen Entfernung hat schon mancher europaische Botaniker diese Statte der Wiss- enschaft ausgesucht und die Kunde von seiner raschen Ent- wickelung in feme Lander getrairen. Aber nicht nur durch den Beweisz sind die Bande zwischen unseren deutschen Botanikern und den am Shaw's Garden arbeitenden Fachgenossen gekniipit worden, auch durch man- nigfachen Austausch von Material und Gedanken haben sich viele Beziehungen ergeben, die heute eigentlich ihren Ausdruck durch das Erscheinen einiger unserer bedeutendsten Fach- genossen, Klebs und Fitting, ihren Ausdruck haben finden sollen. Da dies nun nicht sein konnte und iiuszere Umstande mir als dem einzigen deutschen Botaniker die Teilnahme an Hirer Feier vergonnt haben, so mochte ich nicht versaumen, Ihnen im Namen der deutschen Botaniker die besten Wiinsche aus- zusprechen. Fiinfundzwanzig Jahre erscheinen als eine kurze Spanne Zeit und doch haben Sie ein Reclit den Absehlusz dieser fiinf- undzwanzig Jahre zu feiern. Dieser erste Zeitabschnitt ist einer der wichtigsten, vielleicht iiberhaupt der wichtigste, denn in ihm sind die Grundlagen fur die ganze Zukumf t des Gartens geschaffen worden. Was in diesen Jahren geschaffen worden ist, das haben Sie alle gesehen. Noch erkennt man da und dort die kleinen und einfachen Verhiiltnisse, unter denen die Arbeit begonnen worden ist, aber daneben und sie iiberragend hat schon die neue Zeit dem Garten und seinen Gebauden ihr Geprage aufgedriickt. Uberall sieht man, mit welcher Plan- maszigkeit und Groszziigigkeit die Entwickelung gefordert worden ist und wie sowohl der wissenschaftlichen Arbeil, wie der Nutzbarmachung fur die grosze Allgemeinheit in jeder Weise Rechnung getragen wird. Aber auch denen, die nicht in der Lage sind, die Schatze des Gartens, der Laboratorien direkt zu benutzen, haben Sie eine Quelle der Belehrung und Anregung gegeben durch die Herausgabe der beiden periodischen Schriften 'Annals of the Missouri Botanical Garden' und 'Missouri Botanical Garden 1915] ANNIVERSARY CELEBRATION — BANQUET 13 Bulletin,' von denen die erste fur die Gesamtheit der bo- tanischen Welt bestimmt ist, wahrend die letztere sich an alle die in Ihrer eigenen Heimat wendet, die fur die Botanik als scientia amabilis Sinn und Verstandnis haben. So gehort denn keine grosze Prophetengabe dazu, dem Shaw's Garden eine weitere gedeihliche Entwickelung vorher- zusagen. Dasz aber auch die deutschen Botaniker immer da, wo sie konnen, und wo ihre Mitwirkung erwiinscht ist, gerne mit Ihnen Hand in Hand arbeiten werden, dafur bringt Ihnen die Art der deutschen Wissenschaft, die stets die Forderung jeglicher Forschung zum allgemeinen Besten im Auge gehabt hat und auch in der Zukunft als hochstes Ziel im Auge behalten wird, den Beweis. Meine Wiinsche aber erlauben Sie mir zusammenzufassen in den Ruf : Hortus botanicus Shawensis vivat, crescat, floreat! (A translation of Dr. Appel's address follows.) For this day which you are celebrating, you had invited also a number of European colleagues and expected that of these a large proportion would participate in the exercises. The causes which have prevented most of your European guests from being present are known to all of you and doubtless are regretted by you all. The expectation of a larger number of foreign representa- tives is justified, for during the years of its existence, the Botanical Garden of St. Louis has deservedly taken its place in the ranks of the larger institutions of its kind, and, despite the great distance, many a European botanist has already sought out this scientific center and carried the message of its rapid development to distant lands. But the ties that exist between our German botanists and their colleagues working at Shaw's Garden have been estab- lished not alone by such visits, but also by the abundant ex- change of material and ideas, in which relationships have developed which to-day were to have found expression through [Vol. 2 14 ANNALS OF THE MISSOURI BOTANICAL GARDEN the appearance and participation of two of our most note- worthy colleagues, Klebs and Fitting. But since this could not be, and circumstances have gra- ciously willed it that I should be the only German botanist to participate in your celebration, I wish to express to you on behalf of the German botanists our best wishes. Twenty-five years appear as a short interval of time and yet you have a right to celebrate the completion of these twenty-five years. This first period is one of the most impor- tant, if not the most important, for in it have been established the foundations for the entire future of the Garden. You have all seen what has been created in these years. One still recog- nizes here and there the simple conditions under which the work was started, but these are eclipsed by the imprint which later years have left on the Garden and its buildings. One sees everywhere with what ability and foresight the develop- ment of the Garden has been promoted and every provision made for the scientific work and the increased usefulness of the Garden to the public. But you have also provided a source of information and stimulation to those who are not in a position to directly make use of the resources of the Garden by the publication of the two periodicals, 'Annals of the Missouri Botanical Garden' and 'Missouri Botanical Garden Bulletin,' of which the former is intended for the entire botanical world, whereas the latter goes to those in your home who have an interest in, and an understanding for, botany as a scientia amabilis. It does not, therefore, require a great gift of prophecy to predict for Shaw's Garden a further deserving development. Wherever German botanists can help and wherever their cooperation is desired, they will always gladly work hand in hand with you, proof of which is furnished by the very char- acter of German science, which has always sought to further each and every investigation for the greatest general good, an ideal which will not be lost sight of in the future. My wishes you will permit me to express thus : Hortus botanicus Shaivensis vivat, crescat, floreat!' 1915] ANNIVERSARY CELEBRATION BANQUET 15 The Toastmaster next called upon Professor N. Wille, of the University of Christiania, Christiania, Norway, as follows: > We have also a friend and botanist from Norway, who, I understand, had a rather peculiar experience in this country. He told me that he had for forty-eight hours or more lost his better half by having the tickets and she starting without any Pullman accommodations. I know he can talk to us interest- ingly, and we will be glad to hear from Professor N. Wille, of Christiania. PROFESSOR N. WILLE The Members of the Board of Trustees, Fellow Scientists, Ladies and Gentlemen: I am deeply grateful to the members of the Board of Trustees of the Missouri Botanical Garden for the kind invitation to participate in this celebration. Had it not been for this I should perhaps never have known America. In the short time that I have been here I have learned much, and I only regret that it is not possible for me to remain in your country longer. When I see the splendid botanical equipment of the Missouri Botanical Garden, I can only lament that it has not been possible for me to prosecute my work under such unusually favorable circumstances. My best wishes for the continued scientific development of the Missouri Botanical Garden. In introducing Captain Henry King, the Toastmaster spoke as follows: We have now reached one of the very many interesting sub- jects of the evening, namely the press. Who is there among us who has not, at some time and some place, received flattering notices at its hand, while again, hard knocks, administered without warning and at the most unexpected moment. If I may be permitted to make a suggestion to 1 the speaker who is to follow me, it is that he go easy with us scientists and delvers in the soil, and in the language of a son of Erin's Isle. "If vou can't aro easy, go as easy as you can." It my privilege to introduce Captain Henry King, Editor of the 'St. Louis Globe-Democrat CAPTAIN HENRY KING It is the paramount duty of the newspaper editor to tell the truth. I do not mean literally and completely, but approxi- [Vol. i 10 ANNALS OF THE MISSOURI BOTANICAL GARDEN mately and within the rule of reason and the zone of safety the Less is expected of other would not so often find it so hard to get the truth when he wants to print it. Take, for example, the tremendous and de- plorable situation now presented in Europe. With all our anxiety and all our facilities, we can not be certain how mucli or how little of the wild and whirling daily reports from there news from hell, so to speak— is dependable. We have not yet even found out definitely what it is all about, and why hun- dreds of thousands of industrious and inoffensive citizens have been taken from their homes and affairs, and sent forth with all kinds of murderous weapons to slay one another as fast as possible. The most that we can be sure of is that a war of unparalleled dimensions and appalling severity is raging, and that about the only really good thing in it is that white mes- senger of pity an. I succor, the Red Cross nurse. And yet I am assured by a leading St. Louisan just returned from the seat of war that the reports in the St. Louis papers are more rational, consistent and enlightening, after all, than those in the papers of any of the cities on the other side of the Atlantic. This man's word is good and his judgment accurate. You all know him. I refer to the Hon. Charles Nagel. The lesson of Mr. Nagel's gratifying statement is a timely and an important one. It goes to show that in a case of world- wide interest and illimitable consequences, where the truth veritably lies at the bottom of a well, the St. Louis press gets nearer to it by care and candor, by unprejudiced analysis and fair-minded discrimination, than the press of Europe. This example is an extreme one, perhaps, but I feel safe in saying that it is characteristic and relatively prevalent in all cases. I am here, as you have been advised, to talk about 1h<> press, or at least to use it as a text. You do not expect me, I am sure, to stand here on this festive and botanical occasion and confess the sins of my esteemed contemporaries, or to acknowledge my own, for that matter. So, if you please, I am going to side- step the sins, for the present, and declare from personal knowl- edge and daily comparison that St. Louis has ample reason to be proud of her newspapers. They are not perfect, to be sure 1915] ANNIVERSARY CELEBRATION — BANQUET 17 which is only saying that human life is not perfect, for they are made out of life as life is lived in this goodly city and else- where from day to day. They tell you the current history of the community, of the country, of the universe, and they tell it as correctly as the limitations of human nature permit. They have defects of temperament, faults of accident and mis- information, I frankly admit. If they had not these delin- quencies, mingled with their excellences, as has the life out of which they are made, they would soon become too good for this world and their home would be in heaven, and you would not have any use for them here on this rolling and imperfect planet. They make mistakes, yes — just as you do, and all men (and some women) do, just as the busy life out of which they are made is in great measure a matter of mistakes, which con- stitute what we call experience, and experience is only another name for news. Bear with me, I beg you, if I seem to be too ardent in this topic of the St. Louis press. But I am putting aside, for this occasion, the proverbial modesty of my profession, with a view to telling you the naked truth as if I were under oath. And let me remind you, while I think of it, that the only monument in the world to "The Naked Truth" stands only a short distance from where we are assembled, and its purpose is to typify and commemorate the lives and services of three great St. Louis newspaper editors, Schurz, Preetorius and Daenzer. I am talking to you of the successors of those men, whom I know like a book — my neighbors, my friends, my fellow-workers — ,the men who direct and adorn and give tone and influence to the St. Louis press. I know them to be tireless in their pursuit of facts, in their zeal for the public welfare, in their ambition to promote the growth and progress of this admirable city. It is sometimes said in criticism of them that they are governed mainly by commercial considerations, and one of the pestif- erous sort of professional reformers has lately sent forth a book in which he goes so far as to charge that their policies are absolutely dictated by their big advertisers. Well, if it wasn 't for the big advertisers, you would hardly be able to get the modern wonder and recognized necessity of a daily newspaper [Vol. 2 18 ANNALS OF THE MISSOURI BOTANICAL GARDEN for the absurd price of a penny a copy, the cheapest of all known commodities of general use ; and I often think that the advertisements constitute the most interesting and serviceable part of the paper. That is not the only reason why we print so many of them, I am bound to admit, but it certainly tends to ameliorate the condition and to make the habit almost in- nocent. As for the advertiser as a dictator of editorial policy, we do not find him very insistent or obstreperous. In a life- time of experience, I have never yet known an advertiser to solicit any selfish advantage or assert any right of arbitrary interference on account of his patronage ; but it is a common thing to have them come forward in earnest and practical support of projects for the common good. We owe it largely to the advertisers, the business men, that we have the Veiled Prophet with us every year; that we had an incomparable World's Fair; that we produced the unequaled Pageant and Masque; and I don't believe they will permit the reproach of failure to overtake the Symphony Orchestra. And I'm going to include the Free Bridge in this assurance, though just now I do not see any practicable way to connect with it. This brings me to the point of chief interest, to the Missouri Botanical Garden, with its immense display of floral splendor, its infinite sources of delight and instruction, of admonition and of consolation. I wish I could botanize about it in the thorough and skillful manner of our distinguished scientific visitors. But alas, I have to make the bashful admission that I probably know less about botany as a science than any other person on your program to-night — unless it may be your Toastmaster. The fact is, I have had less to do with flowers than with quadrupeds, such as the Donkey, the Bull Moose, and the Elephant — God bless him — begging the pardon of those of you who don't happen to like him as well as others of us do. But I am tolerably familiar with the part which flowers have played in the affairs of the world. I know how all literature is pervaded by their fragrance and their symbolism. I am not unmindful of their cherished associations in the lives of all classes, from the cradle to the grave. I know how, in many instances, when wisdom reaches its limit and language fails, 1915] ANNIVERSARY CELEBRATION BANQUET 19 they have the gift of talking to us and for us, in a form of expression which we can grasp only with our feelings and emotions, and which our hearts rather than our heads must interpret and utilize. But I must not deviate too far from the relation of the editor to floriculture, which is similar to that of the boy in Mr. Lincoln's story who, being asked if he liked gingerbread, re- plied, you remember, ' ' I reckon I like gingerbread better than any boy in this town, and get less of it. " So it is mainly with the editor and the bouquets. He is more apt, as a rule, to have stale vegetables thrown at him, figuratively speaking, and to be condemned to wait for his flowers until he reaches that point in his career where he no longer has use for anything else. But, happily, the editor is nothing if not a philosopher. The discipline of his profession teaches him patience and tolerance and sweet reasonableness. In the nature of things, he gives more attention to other people's affairs than to his own — so much so, indeed, that now and then he is accused of being over- zealous, not to say over-inquisitive, in that respect. If a bouquet comes his way it surprises and confuses him, since it contradicts his personal experience that if virtue be not its own reward, then it usually remains unrewarded. Nevertheless, he goes on boosting instead of knocking, because it is his mission to spread the gospel of good cheer and make more room in the sun for those who inhabit the earth. He welcomes particularly an occasion like this, where he can help to cele- brate the choice taste, the fine civic spirit, the munificent public benefaction of a man like Henry Shaw. And his pleasure is doubled when to such an opportunity is added the chance to compliment the Missouri Botanical Garden upon having for President of its Board of Trustees a man with the many ex- cellent qualities of Edwards Whitaker. Science is the basis of the great enterprise which Mr. Shaw founded, of course, but science needs trained business sense to invest its service with the highest practical usefulness. Mr. Whitaker has shown in a marked degree his realization of the possibilities of his posi- tion, and the steps by which the benefits of Shaw's Garden, as we familiarly call it, can be materially multiplied. I feel [Vol. 2 20 ANNALS OF THE MISSOURI BOTANICAL GARDEN authorized to say that in this important work he will have the hearty cooperation of the St. Louis press ; and I am sure that he will in turn see to it that the editors get all the floral tributes that are due to them, at least when the time arrives for them to confront the ultimate River of Separation, and each of them shall need something of that sort to waft aloft in his behalf the beautiful message of Tennyson — "For though from out our bourne of time and place, The flood may bear me far, I hope to see my Pilot face to face When I have crossed the bar." In the following words the Toastmaster called upon the next speaker of the evening, Dr. William G. Farlow: We have with us this evening a guest who, I can truth- fully say, is loved by every botanist in America, and I can also assert without fear of contradiction that he is recognized as their dean. I am proud to introduce Dr. William G. Farlow, of Harvard University. may DR. WILLIAM G. FARLOW Mr. President and Ladies and Gentlemen: As I look upon this company and see how many there are here, all of whom are interested in the St. Louis Botanical Garden, I can't help asking myself the question : " Why are they interested in the Garden? " Some have one reason; some have another. Some like it for the flowers that are shown there ; some like it for the scientific work done there. But whatever their reasons be, I would like to take advantage of this occasion to say a few words about what seems to me to be the true object and aim of botanical gardens. Let us go back to history. The first garden on record, I believe, was the Garden of Eden. That garden unfortunately was obliged to be closed to the general public only a short time after it was opened. But we learn some lessons even from the Garden of Eden. In the first i>lace, do not mix zoology and botany. The Garden of Eden was not purely a botanical gar- den. You know what the snake did and will always do in botanical gardens. There is another curious thing about the 1915] ANNIVERSARY CELEBRATION BANQUET 21 Garden of Eden. It is the only garden I ever heard of from which people were excluded because they had just begun to learn something, and it seems to be exceedingly cruel that they should have been turned out into a cold world merely because they knew something. But it is a long step from the Garden of Eden, and history is a little more accurate in recent times than it was then. The traditional botanical garden, the one which has existed for centuries in Europe and to a less extent in this country, was a place where the seeds of a great many plants were sown ; some came up and some did not, but they were all labelled. Now many plants are annual but labels are perennial and the un- fortunate result in many of the older gardens was that there was a luxuriance of labels and a comparative poverty of plants corresponding to the labels. The ideal garden is nature. We can never equal nature in anything like proximate perfection. Go up in the mountains or go out into the woods. You see nature where it has existed for ages, the result of centuries of work. What we see is not what has been planted a few years before. It is the result of the conflict of ages going on between natural forces, and what we see is the final result, such as can not be obtained by man. We find plants which grow where they naturally grow ; we see <^ moss where moss should grow ; we see trees where trees should H~" be. In a botanical garden of the present day, such as the Mis- souri Botanical Garden, we should imitate nature as far as is possible in a limited space and offer to the general public and the special students of botany an epitome of the vegetation of the world. Those of our botanists who visited the Garden yesterday and to-day saw a superb display of cosmos. I don't know that St. Louis people fully appreciate what a fine exhibition of flowering plants we have seen here, but the cosmos are per- fectly magnificent and you have reason to be proud of them. I hope your spring flowers are equally splendid, and there is no reason why in the summer you can't have groups of equally fine character. The old-fashioned botanical gardens had no beauty whatever. They were simply artificial and repulsive, { [Vol. 2 22 ANNALS OF THE MISSOURI BOTANICAL GARDEN but at present a botanical garden must in the first place be beautiful. Although beauty is not the end of everything, we begin with beauty and end with science both practical and theoretical. Besides the flower beds and hothouses the casual visitor notices certain buildings of considerable size scattered here and there. What they are for is not perhaps known to many of those attracted by the floral display. Without these buildings and their contents and the experts in charge of them there could be no floral display of any real importance. Al- though they add little to the beauty of the Garden, in these buildings is done the work which gives to the Garden its scien- tific value and entitles it to recognition throughout the botan- ical world. The very valuable library and herbarium are, in a sense, the soul of the Garden, since from them is obtained a knowledge of the plants cultivated, and they are a necessity to those carrying on research in the laboratories. At this late hour I cannot enter into details. It should be said, however, that for the library and herbarium, fire-proof buildings, always expensive, are necessary since if destroyed they could not be replaced by insurance. The laboratories for research are in a somewhat different position. The value of research in vegetable physiology and pathology and other sub- jects other than systematic botany, which is, of course, carried on in the herbarium, cannot be overestimated. Convenient and well-equipped laboratories are a necessity in a modern garden. They do not, however, require expensive fire-proof buildings. The outfit of the laboratories should be up to date, but new and improved instruments are invented from year to year and an occasional conflagration is not to be dreaded since the insurance on the older instruments can be used for pur- chasing better new ones. Furthermore, the trend of original research is constantly changing and, in trying to adapt them- selves to the current demands of the scientific public, the na- ture of the work done in research laboratories and in conse- quence their equipment vary from time to time. As I look at my audience, I am reminded of something I saw in the train coming to St. Louis the other day. I picked up what I believe was the last number of 'Life,' and glanced at 1915] ANNIVERSARY CELEBRATION BANQUET 23 a cartoon, a crowd of persons seemingly very much pleased, and wishing to know why they were hilarious, I saw that the title was the ' ' Millenium Celebration in Honor of the Abolish- ment of After Dinner Speeches." Your faces remind me somewhat of those of the crowd I saw in 'Life,' and I now close, fearing that you may be hoping that the millenium will arrive before we have another twenty-five year dinner, when I shall not be with you. The Toastmaster next called upon the Hon. Charles Nagel, of St. Louis, in the following words: Our city has had a number of her sons, and adopted sons, called to occupy positions of responsibility at the National Capital, one of whom, after four years ' service in the Cabinet, has returned to the city of his adoption; and I am proud to introduce the Hon. Charles Nagel, ex-Secretary of Commerce and Labor. HON. CHARLES NAGEL Mr. Toastmaster, Ladies and Gentlemen: It appears to me that the last speaker was both wise and unkind in referring to the illustration from 'Life' at the close of his speech. I can assure him that my embarrassment was sufficient without that reference. In endeavoring to account for my presence in a family of botanists, I have been compelled to go pretty far back in my life and to recall an incident when an aged grandmother, whom I never knew, sent me what Dr. Appel will pardon me for call- ing a "Botanisirbuechse," to encourage me in the collection of plants. It was only a trifle at the time, and yet I imagine I share the experience of most people in tracing my interest in nature to that early incident in my life. I would say that my love of nature is such that I would rather have my child love the virility and strength of an oak leaf than all the bouquets and flowers that can be gathered. I believe that real love for the strength of nature is what we need, and not the pampering influences of the selected flower. I believe in the forests of New Hampshire that my friend. Dr. Farlow, loves; and I can see him now searching 24 ANNALS OK THE MISSOURI BOTANICAL GARDEN [Vol. 2 for his specimens there, but never unmindful of the grandeur of all nature to which his specimen furnishes only a clue. But studying of the plant means more than that. It means the reason of nature. I have sometimes thought that if we knew more of the reason for the decline of one plant and the triumph of another, we would have a better understanding of the meaning of the inevitable and unavoidable conflicts that are now tearing the world apart ; and we Americans, if we knew more of the generating influence of the one and the survival of the other, would appreciate that it takes conflict and danger to make strong men and women. I do not want to go too far, but while a park need not be a botanical garden, no park can succeed unless it has applied to it the science and the work of the school of botany. We can not have the city beautiful, with all our preaching, until we understand the true meaning of a school of botany and of our, botanical gardens. If any one doubts it, let him look abroad. He who has seen the beautiful forests about Paris, the splendid forests about Berlin, the wonderful forests about the Hague, will say to himself, "Yes, this is nature, profound and beauti- ful"; but it is not an accident. It is the result of nature's force guided by experience and science. That is what we need — politics, government, must take into counsel the man of wisdom and experience to produce those wonderful results which so far we cannot imitate. There is more than that. Abroad, not only the government utilizes the information which these men and women of science have to give, but every man and woman throughout the land con- sciously or unconsciously is influenced by the same teaching. Wherever you look and whatever you see demonstrates to you the result of that kind of work. It means not only the flowers and the plants, but it evidences the happiness of family life. Every field shows it; every home and every garden patch shows it. That is the lesson we have to take unto ourselves in this, our new country. That is what we have to do if, as a people, we are to succeed; and it is for this reason that we welcome the greetings of the distinguished guests who have joined us to-night. 1915] ANNIVERSARY CELEBRATION — BANQUET 25 True, all the countries are not represented ; but we have the right to say to ourselves that science and civilization stand above all the conflicts of the day. Ultimately, the very nations who are now engaged in this conflict will again have to unite their hands to bear the standard of civilization jointly upon the Continent ; and we have a right to say to-night that while only a few countries are represented, from the standpoint of science and civilization broadly speaking, the few representa- tives are here to speak to us for all the civilized nations of the world. The last speaker of the evening, Dr. George T. Moore, was called upon by the Toastmaster aa follows: Mr. Shaw's will requires the Board to appoint a Director of the Garden, who is to reside upon the Garden grounds. He is virtually the executive of the board and the Garden Committee so far as Garden matters pertain, and he might be compared to the man behind the gun, as much of the success of the Gar- den depends upon him. The Director is known to so many of you, an introduction seems hardly necessary ; but for form 's sake I take pleasure in introducing Dr. George T. Moore, Di- rector of the Missouri Botanical Garden. DR. GEORGE T. MOORE It was my pleasant task on yesterday to welcome those who honored us with their presence at the first formal exercises celebrating the passing of a quarter century in the life of the Missouri Botanical Garden. To-night has been delegated to me the duty of closing what at least for the Garden has been a most memorable festival, one which long will remain that delight which, joined with memory and hope, constitutes a perfect occasion. An after-dinner speech is sometimes regarded as a sort of verbal culture medium for the propagation of words, and it is remarkable with what rapidity those who confine their efforts to media containing no solidifying substance can cloud an otherwise clear situation. With the example set me to-night, it behooves me to speak directly to the point and not spoil an evening which thus far has been faultless. [Vol. 2 26 ANNALS OF THE MISSOURI BOTANICAL GARDEN That the Missouri Botanical Garden was fortunate in its founder, I have tried to indicate early on this anniversary occasion, and it is not necessary, even if it were possible, for me to add anything to the appreciative words which have been spoken at this table. I do feel, however, that perhaps not enough emphasis has been placed upon the fact that it is the organization of the Board of Trustees which furnishes the real reason for this anniversary, and that in honoring Mr. Shaw and in praising the courage and skill which he displayed, we are apt to forget the prolonged efforts of those men who have unselfishly given of their time and thought to make the dream of Henry Shaw come true. You botanists present know that he who would keep up his scientific fire must also have the means of keeping up his ma- terial woodpile. Certainly no place in this country has a trust been so closely and so successfully administered as by that body of men who, from the very first, have labored without remuneration or recognition from those they served, the Board of Trustees of the Missouri Botanical Garden! Every citizen of St. Louis, every visitor to the Garden, every botanist or individual who may have been assisted by the fa- cilities of the Garden, library or collections, has reason to echo the words of George Washington, which, slightly altered, are just as applicable to the Board of Trustees of the Missouri Botanical Garden throughout its existence, as they were to Benjamin Franklin: "If to be venerated for wisdom, if to be admired for talents, if to be esteemed for service, if to be loved for devotion, can gratify the human mind, they must have had and have thepleasing consolation that they had not and will not have lived in vain." In the long run, which is a sort of mathematical name for Providence, such services have their reward, but every twenty- five years, I think the Board of Trustees as a body — for the individuals wouldn't permit such a thing — should at least be entitled to a public statement of the facts. We are grateful to all who, through their active participa- tion or by their presence at the sacrifice of valuable time and by long journeyings, have contributed to the success of this 1915] ANNIVERSARY CELEBRATION BANQUET 27 occasion. Especially do we owe thanks to those who by presenting such splendid papers have made the programs such as will be difficult to surpass in the future. The celebration of an anniversary is a ground of congratu- lation or regret according as it marks the progress or decline of the event it commemorates. My only hope at this time is that on the next anniversary occasion of the Missouri Botan- ical Garden the advances made along the lines of the various activities in which the Garden is interested, may be far beyond those of the present, and that the celebration will exceed the twenty-fifth as many times as the Garden is years older. The Toastmaster concluded the program of the evening with the following remarks : The hour is growing late. A few words before parting. On behalf of the Board of Trustees of the Missouri Botanical Gar- den, I wish to thank one and all for their presence here this evening, especially those who have journeyed far to be with us, and to express the hope that we may enjoy this pleasure many years to come. Good night ! ADDBESS OP WELCOME GEORGE T. MOORE Director of the Missouri Botanical Garden It becomes my pleasant duty at the beginning of the pro- gram celebrating the twenty-fifth anniversary of the organiza- tion of the Missouri Botanical Garden to formally do what I am sure has already been done over and over again by each member of the staff — welcome most heartily those guests who have done us the honor of coming to share with us the simple, yet I hope adequate, ceremonies which have been arranged for this occasion. At one time it was expected that this welcome would be extended by Mr. Houston, who, because of his triple offices, as a member of President Wilson's cabinet, a Trustee of the Missouri Botanical Garden, and Chancellor of Wash- ington University, as well as the grace with which he would have addressed you, would most suitably have performed this duty. Pressure of public work has prevented the Secretary of Agriculture from being with us, however, and I can only hope that you will feel that the welcome extended to you now carries with it as much cordiality and good will as if it came from an officer of the Government, the Garden, and the University. Nothing could be more fitting at this time than some account of the life and work of the founder of this Garden, who de- serves, both because of his far-sighted planning and his mag- nificent gift, to rank as America's foremost patron of botany. Most of you are no doubt familiar with the simple but im- pressive biographical facts concerning Mr. Shaw. How he came to this country from England with his father in 1818, being eighteen years of age, and after brief stays in Canada and New Orleans, settled in St. Louis. With a small stock of hardware he began business in one room, which also served as his bedroom and kitchen. From such a small beginning — and this on borrowed capital — scarcely more than twenty years were required by this pioneer merchant to amass a Ann. Mo. Bot. Gard., Vol. 2, 1915 (29) [Vol. 2 30 ANNALS OF THE MISSOURI BOTANICAL OARDEN fortune, for at forty years of age Mr. Shaw retired from active business to devote the remaining forty-nine years of his life to travel, and later to the active and remarkably intimate crea- tion and management of a garden — that garden of which, be- cause of his intelligent planning and unprecedented fore- - thought and liberality, we are to-day celebrating the silver anniversary. The advice and counsel of such men as Dr. George Engel- mann, Sir William Hooker and Professor Asa Gray was freely sought and as freely given. In this connection I should like to read a letter from Sir Joseph Hooker, written June 17, 1888 : "The Camp, Sunnydale, England. "My Dear Mr. Shaw :— "I have just received your most handsome present of Engelmann's Botanical Works, edited by our dear late friend, Dr. Gray, and 1 do thank you most heartily, no less for your kind gift than for the effective service to botany that this most valuable contribution to the science renders. It is indeed a noble tribute to a man whose labors as a most conscientious and painstaking botanist have never been surpassed, and I prize it for the sake of the man whom I knew so well and esteemed so highly. I shall never forget my visit to him and to you and the afternoon I spent in your garden and museum at St. Louis, in company with Dr. and Mrs. Gray. "I have been most interested in all that Dr. Gray told me last year about the noble botanical institution that you have founded and in his hopes that it would be a center of diffusion of knowledge, the influence of which would be felt far and wide. "I think that he was more proud of your consulting him in the matter of its organization than of any of the many services which he had rendered to American botany, and he certainly regarded his labor with you as the most pleasant episode of his later years and by far the most important. "Believe me, my dear sir, most faithfully and gratefully yours, Joseph D. Hooker. y> The country home of Mr. Shaw was built on these grounds in 1849, and the breaking of the prairie for his garden is said to have begun in 1857. There is no record of any formal opening of the Garden to the public, however, the date 1858 on the entrance of the main gate probably being the year it was erected rather than the time it was first opened to visitors. The small " Museum and Library," as it is designated in the 1915] MOORE ADDRESS OF WELCOME 31 stone over its entrance, was built in 1859, and this same year the installation of the Bernhardi Herbarium, previously pur- chased in Europe, marked Mr. Shaw's intention to make the Garden a center for scientific investigation and research. How successfully the founder of the Missouri Botanical Gar- den incorporated this idea in the document intended for the guidance of those who should administer this bequest, is evi- denced by the remark of Judge Medill, one of the first members of the Board of Trustees, who, after the reading of the will, exclaimed : ' ' That is a scientific institution and much should come of its services to botany ! ' ' Mr. Shaw died August 25, 1889, and on September 10 the formal organization of the Board of Trustees, created by his will, took place. This is the anniversary we celebrate, for, as I have indicated, it is the only definite anniversary we have. Certainly asa" botanical institution, public in character, ' ' the Missouri Botanical Garden began its existence upon the organ- ization of the trust declared by Mr. Shaw's will. Two other notable bequests of Mr. Shaw require brief men- tion at this time, one indicating his desire for further scientific investigation in botany, the other the love for the beautiful in nature and his wish that all might have unlimited oppor- tunity for acquiring and indulging this same passion. I refer, of course, to the endowment of the Henry Shaw School of Botany of Washington University, and the gift of Tower Grove Park to the city of St. Louis. The first is, owing to the broad-minded liberality of the Board of Trustees of the Gar- den and the untiring and unselfish efforts of its staff, taking a place among similar schools of the kind of which Mr. Shaw would not himself be ashamed. The latter, under the fatherly care of Mr. Gurney, its first and only Superintendent, whom we are proud to call the Head Gardener Emeritus of the Mis- souri Botanical Garden, is nobly fulfilling the purpose for which it was created. It is proper, then, that this company of scholars should as- semble here to do honor to the memory of Henry Shaw, to rejoice with us for the successful completion of twenty-five years of usefulness of the Missouri Botanical Garden. [Vol. 2, 1915] 32 ANNALS OP THE MISSOURI BOTANICAL GARDEN Both personally and in my official capacity I welcome you not only to these ceremonies, but as cooperators in an era of even greater effort and achievement for the cause of the science which Mr. Shaw loved and honored and encouraged. THE VEGETATION OF MONA ISLAND 1 N. L. BRITTON New York Botanical Garden During the progress of the scientific survey of Porto Rico, organized by the New York Academy of Sciences with the aid of the American Museum of Natural History, the New York Botanical Garden and Columbia University, in coopera- tion with the Porto Rican Insular Government, exploration has been carried out not alone on the mainland of Porto Rico but on several small islands adjacent and politically a part of that colony. Two of these islands lie in the Mona Passage between Porto Rico and Santo Domingo, and being scientific- ally almost unknown, were made points of examination in February, 1914, when I visited them in company with Mr. John F. Cowell, Director of the Buffalo Botanic Garden, Dr. Frank E. Lutz, Assistant Curator of Invertebrate Zoology in the American Museum of Natural History, and Mr. W. E. Hess, Plant Propagator of the Porto Rico Agricultural Ex- periment Station at Mayaguez. The trip was made in a sloop chartered at Mayaguez. Desecheo Island, lying about eighteen miles northwest of Mayaguez, was first visited, and explored during two days; this island is somewhat more than one square mile in area, bordered by rocky coasts, rising abruptly into several hills, and covered with low trees and shrubs. Its flora is essen- tially identical with that of the drier parts of Porto Rico and of Santo Domingo; the small tree Morisonia americana and the snowy cactus (Mamillaria nivosa) have, however, not yet been found on the Porto Rican mainland, although both occur on the Island of Culebra east of Porto Rico, and neither of them is known on Santo Domingo. The cactus Opuntia haitiensis, plentiful there, is otherwise known only in His- paniola, and the shrub Torrubia discolor of Hispaniola and Cuba has not been found on Porto Rico. The collection made 1 Issued May 17, 1915. Ann. Mo. Bot. Gard., Vol. 2, 1915 (33) [Vol. 2 34 ANNALS OV THE MISSOURI BOTANICAL GARDEN by us on Desecheo, together with one made by Professor F. L. Stevens and Mr. W. E. Hess in May, 1913, shows that the spermatophytes of Desecheo number about 90 species; further intensive exploration might reveal a few more. A single species of fern was seen, four species of mosses, and two species of hepatics. As there is no probability of this little island ever having been a part of the Porto Rico main- land, its plants must have reached it by natural agencies ; there are probably as many fungi and lichens as of other land plants collectively, so the total land flora of Desecheo probably includes at least 200 species. Mona Island, lying about thirty miles to the southwest of Desecheo, in the middle of the Mona Passage between Santo Domingo and Porto Rico, has an area of approximately twenty square miles. Prior to our visit, only one botanical collection had been made there, when it was visited by Professor F. L. Stevens in 1913, at which time he obtained specimens of about 150 species of flowering plants, and gave especial atten- tion to the parasitic fungi. The considerable land area of this island made a complete knowledge of its flora desirable, from the standpoint of geographical distribution of West Indian plants, and we were able to devote five days to collect- ing. The greater portion of Mona is a limestone plateau elevated from 125 to 175 feet, the surface of this plateau being nearly level and devoid of hills; its soil is very sparse, con- sisting altogether of reddish loam in depressions of the lime- stone surface, and not of considerable extent at any point visited by us. The limestone is evidently very porous, and there are no streams or ponds, and only a single spring was seen; the limestone is honeycombed with caves and caverns, some of them of considerable size. The rainfall is evidently considerable, but there are no records of its amount. Despite the paucity of soil, the whole plateau is rather densely covered with shrubs and low trees of a considerable number of species, their roots, for the most part, penetrating into crevices of the limestone. Herbaceous vegetation is restricted comnarativelv few of this plateau, and in places are very abundant, the snowy 1915] BRITTON VEGETATION OF MONA ISLAND 35 (Mamillaria nivosa) being more plentiful here than on any other island visited by us; Opuntia Taylori, hitherto known from Hispaniola, Culebra and the Virgin Islands, was found as a single colony; this has not yet been detected on the Porto Rican mainland. The limestone plateau of Mona is bordered nearly through- out by steep escarpments and is accessible at but few points, except along the southwestern side, where there is a low plain several miles long and averaging about half a mile wide, from which the plateau is reached at a number of points over a talus of large limestone blocks. At the foot of the escarpment and of the talus on this southwestern side, the moistest condi- tions of Mona occur, and several species of trees here reach large size, notably the manchioneel (Hippomane Mancinella) and two species of Ficus. Here also grow two species of ferns, several bryophytes, and a number of Polyporaceae infesting dead wood. The soil of the narrow plain is more abundant than that of the plateau, permitting agricultural operations on a small scale and supporting a low forest made up of a considerable number of kinds of trees, with more her- baceous vegetation than exists on the plateau. Among rare elements of this vegetation are two orchids, Domingoa hyme- nodes, hitherto known from Hispaniola and Cuba, and Ibidium lucayanum, of Porto Rico, Anagada and the Bahamas. The coastal sands, which extend almost uninterruptedly along the shore of the plain, are inhabited by characteristic West Indian sand-dune species. Lichens are quite abundant on tree trunks and on rocks of the talus, including a considerable number of species. Pro- fessor Lincoln W. Riddle has examined the collection and has submitted the following report upon them : "The exploration of Mona Island has yielded 42 numbers of lichens, 40 collected by Dr. N. L. Britton, Messrs. J. F. Cowell and W. E. Hess, and 2 collected incidentally by Dr. F. L. Stevens. These 42 numbers represent 26 species in condition for determination. "The species growing on the limestone rocks constitute the most striking and interesting part of the collection. These include four species of Omphalaria, a species of Collema, and a species of the Der- matocarpaceae, which is, unfortunately, sterile and, therefore, not further determinable. The omphalarias are all little known species. [Vol. 2 36 ANNALS OF THE MISSOURI BOTANICAL GARDEN 0. polyglossa Nyl., collected from limestone rocks in Cuba by diaries Wright, and not otherwise known, is apparently common on Mona Island, as it is represented by two numbers, each with several well- developed specimens. There occur also 0. lingulata Tuck., previ- ously know r n from Cuba and Bermuda; a sterile omphalaria related to 0. Wrightii Tuck., but apparently not identical; and one other species of the genus, probably new. It has not yet been possible to identify the species of Collema, and that may also prove to be new. Curiously enough, none of these calciphile species has yet been de- tected among the material collected in Porto Rico. "In marked contrast to the rock-lichens, the bark-inhabiting lich- ens are all common species, widely distributed in Tropical America. The genus Trypethelium is best represented, with the species T. Eluteriae (four numbers), T. ochroleucum, and its variety pallescens, and T. mastoideum (two numbers). There are also such character- istic species as Gr aphis Afzelii, Melanotheca omenta, Pyxine picta, Physcia alba and P. speciosa, Parmclia sulphurata and P. tinctorum, and Ramalina complanata and R. Montagnei. Probably owing to the comparatively unfavorable conditions on Mona Island, the foliose and fruticose lichens are mostly small specimens, not well-developed." The total flora of flowering plants, as indicated by the col- lection made by Professor Stevens and our own, includes about 230 species ; some of them are found only in cultivated grounds on the coastal plain and have probably been introduced by man. The total flora of land cryptogams is probably as great or greater than that of flowering plants, so we may conclude that the land flora of Mona consists of as high as 500 species. So far as the investigation of the collections has proceeded, the only apparent endemic species are a Chamaesyce, which Dr. C. F. Millspaugh has described as new, a Tabebuia, the description of which is herewith included, and two very inter- esting riccias, here described by Dr. Marshall A. Howe. One or more of the lichens may be undescribed. Further explora- tion in Porto Rico and in Hispaniola may very well reveal their presence on these larger islands. It is interesting to have ascertained that the flora of this isolated limestone island is not more highly specialized. It is not necessary, in my opinion, to assume a former land connection between Mona and either Porto Rico or Santo Domingo, because all may readily have reached it through agencies 1915] BRITTON VEGETATION OF MONA ISLAND 37 I append a list of the species collected as thus far deter- mined, and have indicated in this list their known distribution, except that of the lichens and Uredinales, as regards Porto Rico, Curasao, Hispaniola and the Bahamas, the nearest lands to Mona. The names of new species, and new binomials, are printed in heavy face type. List of Species inhabiting Mona Island MONOCOTYLEDONS VALOTA INSULARIS (L.) Chase Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas; Curacao. S YNTHERISMA DIGITATUM ( Sw. ) Hitchc. Frequent in cultivated ground, coastal plain: Porto Rico; Hispaniola; Bahamas. PASPALUM CAESPITOSUM Fluegge Frequent on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. PASPALUM SIMPSONI Nash Collected by Professor Stevens, not found by us: Porto Rico; Bahamas. PANICUM UTOWANAEUM Scribn. Frequent on the coastal plain and on the plateau: Porto Rico; Desecheo; [Cuba; Guadeloupe]. PANICUM BARBINODE Trin. Sandy soil, Playa de Fajaro: native of South America. Naturalized in the West Indies. PANICUM ADSPERSUM Trin. Moist soil, coastal plain: Porto Rico; Bahamas. PANICUM MAXIMUM Jacq. Frequent on the coastal plain: Native of tropical Africa; naturalized in the West Indies. LASIACIS DIVARICATA (L.) Hitchc. Frequent in thickets, coastal plain and plateau: Porto Rico; Hispaniola; Bahamas. CHAETOCHLOA SETOSA (Sw.) Scribn. Frequent on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. CHAETOCHLOA CAUDATA (Lam.) Scribn. Occasional on the coastal plain: Desecheo; [Jamaica; Cuba; St. Thomas]. CHAETOCHLOA IMBERBIS (Poir.) Scribn. Frequent on the coastal plain: Porto Rico; Hispaniola; Bahamas. CENCHROPSIS MYOSUROIDES (HBK) Nash Frequent in cultivated ground on the coastal plain: Bahamas; Cuba. [Vol. 2 38 ANNALS OF THE MISSOURI BOTANICAL GARDEN CENCHRUS ECHINATUS L. Common on the coastal plain and on sand dunes: Porto Rico; Hispaniola; Bahamas; Curacao. CENCHRUS CAROLINIANUS Walt. Collected by Professor Stevens, not found by us: Porto Rico; llisjuvniola; Bahamas; Curacao. ARISTIDA BROMOIDES HBK. Common on the coastal plain: Porto Rico; Bahamas; Curacao. SPOROBOLUS VIRGINICUS (L.) Beauv. Common on coastal sands and on the coastal plain: Porto Rico; Hispaniola; Bahamas. SPOROBOLUS ARGUTUS (Nees) Kunth Frequent in moist soil on the coastal plain: Porto Rico; Hispaniola; Curacao. CHLORIS PARAGUA1KNSIS Steud. Coastal plain, Sardinera: Porto Rico; Hispaniola; Bahamas; Curacao. EUSTACHYS PETRAEA (Sw.) Desv. Common on coastal sands and on the coastal plain: Porto Rico; Hispaniola; Bahamas. ELEUSINE INDICA (L.) Gaertn. Cultivated ground, coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. DACTYLOCTENIUM AEGYPTIUM (L.) Willd. Cultivated ground, coastal plain: Porto Rico: Hispaniola; Bahamas; Curacao. PAPPOPHORUM LAGUIIOIDEUM Schrad. Wet soil, coastal plain, between Sardinera and Ubero: Desecheo [Cuba; St. Eustatius]. ERAGROSTIS CILIARIS (L.) Link Common on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao CYPERUS ELEGANS L. Border of a marsh on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. CYPERUS TENUIS Sw. Occasional on the coastal plain: Porto Rico; Hispaniola. CYPERUS LIGULAR1S L. Marsh, Sardinera: Porto Rico; Hispaniola; Bahamas; Curacao. CYPERUS BRUNNEUS Sw. Common on coastal sands: Porto Rico; Bahamas; Hispaniola; Curacao. FIMBRTSTYLIS SPATIIACEA Roth. Common on the coastal plain: Porto Rico; Bahamas; Hispaniola. SCLERIA LITHOSPERMA (L.) Sw. Frequent on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. ? THRINAX PONCEANA 0. F. Cook Apparently this species, but determined from leaves only. Rare in thickets on the coastal plain, and not found either in flower or in fruit: Porto Rico. TILLANDSIA UTRICULATA L. Common on trees and on rocks: Porto Rico; Hispaniola; Bahamas; Curacao. 1915] BRITTON VEGETATION OF MONA ISLAND 39 TILLANDSIA RECURVATA L. Common on trees and shrubs: Porto Rico; Hispaniola; Bahamas; Curacao. CALLISIA REPENS L. Occasional on the coastal plain and on the plateau: Porto Rico; Hispaniola; Curacao. COMMELINA VIRGINICA L. (0. elegans HBK.) Frequent on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. HYMENOCALLIS EXPANSA Herb. Frequent in coastal sands. Determination from foliage only, therefore un- certain. FURCRAEA TUBEROSA Ait. f. Coastal plain between Sardinera and Ubero; probably introduced from Porto Rico. Determined from leaf specimens only: Porto Rico. IBIDIUM LUCAYANUM Britton Low woods, coastal plain near Sardinera: Porto Rico; Bahamas. EPIDENDRUM PAPILIONACEUM Vahl Common on shrubs and on the ground, coastal plain and plateau: Porto Rico; Hispaniola; recorded from the Bahamas. DOMINGOA HYMENODES (Rchb. f.) Schltr. On small trees between Sardinera and Ubero: Hispaniola [Cuba]. DICOTYLEDONS PEPEROMIA HUMILIS (Vahl) A. Dietr. Shaded limestone rocks near Sardinera. Plants with only the upper leaves opposite: Porto Rico; Hispaniola. CELTIS TRINERVIA Lam. Base of cliffs, Sardinera: Porto Rico; Hispaniola. FICUS LAEVIGATA Vahl Coastal plain and plateau; largest at the bases of cliffs: Porto Rico; His- paniola. FICUS STAHLII Warb. Frequent along the bases of cliffs, eastern edge of the coastal plain. Trees up to 12 m. high. Determined from foliage only: Porto Rico. CHLOROPHORA TINCTORIA ( L. ) Gaud. Base of cliffs, Sardinera: Porto Rico; Hispaniola. PILEA TRIANTHEMOIDES (Sw.) Lindl. Frequent on the coastal plain: Porto Rico. PILEA MICROPHYLLA (L.) Liebm. Occasional on the plateau: Porto Rico; Hispaniola; Bahamas; Curacao. COCCOLOBIS UVIFERA (L.) Jacq. Common on coastal sands and rocks: Porto Rico; Hispaniola; Bahamas; Curacao. COCCOLOBIS OBTUSIFOLIA Jacq. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; ? Bahamas. COCCOLOBIS LAURIFOLIA Jacq. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. [Vol. 2 40 ANNALS OK THE MISSOURI BOTANICAL GARDEN COCCOLOBIS NIVEA Jacq. Base of cliff, Sardinera: Porto Rico; Hispaniola. AMARANTHUS TRISTIS L. Waste and cultivated grounds on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. ACHYRANTHES INDICA (L.) Mill. Frequent in cultivated ground, coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. LITHOPHILA MUSCOIDES Sw. Collected by Professor Stevens, not found by us: Porto Rico; Hispaniola; Bahamas; Curacao. CELOSIA NITIDA Vahl Frequent on the coastal plain: Porto Rico; Hispaniola; Bahamas. MIRABILIS JALAPA L. Waste grounds, uncommon: Porto Rico; Hispaniola; Bahamas. BOERHAAVIA COCCINEA Mill. Common on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. ? PISONIA SUBCORDA T A Sw. Base of cliffs, Sardinera. Trees, 12 m. high or more, barren at the time of our visit and determination therefore uncertain: Porto Rico. RIVINA HUMILIS L. Common on the coastal plain on the plateau: Porto Rico; Hispaniola; Bahamas; Curacao. TRICHOSTIGMA OCTANDRUM (L.) H. Walt. Frequent on the talus, vicinity of Sardinera, forming vines 20 m. long with trunks up to 1.5 dm. diameter: Porto Rico; Hispaniola. PETIVERIA ALLIACEA L. Occasional in thickets on the coastal plain: Porto Rico; Hispaniola; Bahamas. SESUVIUM PORTULACASTRUM L. Common on coastal rocks and sands: Porto Rico; Hispaniola; Bahamas; Curacao. TALINUM PANICULATTM (Jacq.) Gaertn. Coastal plain, Sardinera: Porto Rico; Hispaniola. PORTULACA PHAEOSPERMA Urban Moist soil, coastal plain and plateau: Porto Rico; Hispaniola; Bahamas; Curacao. PORTULACA OLERACEA L. Sandy soil, Playa de Fajaro: Porto Rico; Hispaniola; Bahamas; Curacao. NECTANDRA CORIACEA (Sw.) Griseb. Base of limestone cliff, Sardinera: Porto Rico; Hispaniola; Bahamas; Curacao. CASSYTHA AMERICANA Nees Frequent on the coastal plain: Porto Rieo; Hispaniola; Bahamas. CLEOME GYNANDRA L Waste and cultivated grounds, coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. CAPPARIS CYNOPHALLOIMIORA L. (C. jamaieensis Jacq,) Frequent on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. 1915] BRITTON VEGETATION OF MONA ISLAND 41 CAPPARIS FLEXUOSA L. (C. cynophallophora Jacq.) Common on the coastal plain: Porto Rico: Hispaniola; Bahamas. LEPIDIOI VIRGINICUM L. Common in waste and cultivated ground: Porto Rico; Hispaniola; Bahamas. BRASSICA INTEGRIFOLIA (West) O. E. Schulz Occasional in cultivated ground, coastal plain: Porto Rico; Bahamas. CAKILE LANCEOLATA (Willd.) 0. E. Schulz Common on coastal sands: Porto Rico; Hispaniola; Bahamas. PITHECOLOBIUM UNGIUS-CATI (L.) Benth. Common in coastal thickets and occasional on the coastal plain. All speci- mens examined were spineless: Porto Rico; Hispaniola; Bahamas; Curacao. CASSIA OCCIDKNTALIS L. Sandy soil, Playa de Fajaro: Porto Rico; Hispaniola; Bahamas. CHAMAECRISTA GRANULATA (Urban) Britton. (Cassia portoricensis granulata Urban.) Common on the coastal plain and on sand dunes: Porto Rico. CHAMAECRISTA DIFFUSA (DC.) Britton. (Cassia diffusa DC.) Collected by Professor Stevens, not found by us: Porto Rico; Curacao. ? CAESALPINIA DOMINGENSIS Urban On the plateau, Sardinera. Determined from description: Hispaniola. GUILANDINA CRISTA (L.) Small Occasional in coastal thickets: Porto Rico; Hispaniola; Bahamas. GUILANDINA MELANOSPERMA (Urban) Britton. (Caesalpinia melano- sperma Urban.) Frequent on the coastal plain: St. Croix. GUILANDINA DIVERGENS (Urban) Britton Frequent on the coastal plain: Culebra [St. Thomas]. KRAMERIA IXINA L. Occasional on the coastal plain and on the plateau: Porto Rico; Hispaniola; Curacao. INDIGOFERA SUFFRUTICOSA Mill Cultivated ground, coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. CRACCA CINEREA (L.) Morong Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas; Curacao. STYLOSANTHES HAMATA (L.) Taub. Frequent on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. MEIBOMIA SUPINA (Sw.) Britton Frequent on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas ; Curacao. MEIBOMIA MOLLIS (Vahl) Kuntze Occasional in cultivated ground on the coastal plain: Porto Rico; His- paniola; Bahamas; Curacao. BRADBURYA VIRGINIANA (L.) Kuntze Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. [Vol. 2 42 ANNALS OF THE MISSOURI BOTANICAL GARDEN GALACTIA STRIATA (Jacq.) Urban Frequent on the coastal plain and on the plateau. A race with small leaflets and slender-peduncled racemes: Porto Rico; Hispaniola. CANAVALIA LINEATA (Thunb.) DC. Common on coastal sands: Porto Rico; Hispaniola; Bahamas. ? DOLICIIOLUS MINIMUS (L.) Medic Cultivated ground, Ubero. A race apparently of this species, with thick leaflets, strongly veined; not found either in llower or in fruit, the determination, therefore, uncertain. DOLICHOLUS RETICULATUS (Sw.) Mi lisp. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. ERYTHROXYLON AREO LATUM L. Frequent on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. GUAIACUM SANCTUM L. Frequent on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. ZANTHOXYLUM PUNCTATUM Vahl Coastal plain between Sardinera and Ubero: Porto Rico; Hispaniola. AMYRIS ELEMIFERA L. Occasional on the coastal plain: Porto Rico; Hispaniola; Bahamas. SURIANA MARITIMA L. Common on coastal sands: Porto Rico; Hispaniola; Bahamas; Curacao. ELAP11RIUM SIMARUBA (L.) Rose Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas; Curacao. STIGMAPHYLLON LINCULATUM (Poir.) Small Common on the coastal plain and on the plateau: Porto Rico; Hispaniola. BYRSONIMA LUCIDA (Sw.) L. C. Rich Occasional on the coastal plain: Porto Rico; Hispaniola; Bahamas. XYLOPHYLLA EPIPHYLLANTHUS (L.) Britton. (Phyllanthus Epiphyl- Ian thus L.) Common on the coastal plain: Porto Rico; Hispaniola; Bahamas. PHYLLANTHUS NIRURI L. Cultivated ground, coastal plain. Not collected: Porto Rico; Hispaniola; Bahamas ; Curacao. CROTON LUCIDUS L. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. CROTON DISCOLOR Willd. Common on the plateau: Porto Rico; Hispaniola. CROTON BETULINUS Vahl Common on the coastal plain and on the plateau: Porto Rico; Hispnniola. ARGITHAMNIA CAND1CANS Sw. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas ; Curacao. RICINUS COMMUNIS L. Waste grounds, Ubero: Native of the Old World tropics. 1915] BRITTON VEGETATION OF MONA ISLAND 43 HIPPOMANE MANCINELLA L. Common on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. CHAMAESYCE MONENSIS Millsp. Limestone plateau, Ubero: Endemic. CHAMAESYCE PORTORICENSIS (Urban) Millsp. On limestone rocks, Ubero and Sardinera: Porto Rico. CHAMAESYCE SERPENS (HBK.) Small Moist soil, coastal plain and plateau: Porto Rico. CHAMAESYCE HYPER1CIFOLIA (L.) Millsp. Common in cultivated ground on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. CHAMAESYCE BUXIFOLIA (Lam.) Small Common on coastal sands: Porto Rico; Hispaniola; Bahamas; Curacao. AKLEMA PETIOLARIS (Sims) Millsp. (Euphorbia pet iolar is Sims.) Common on the coastal plain and on the plateau: Porto Rico. POINSETTIA HETER£)PHYLLA (L.) Kl. & Garcke Sandy beach, Play a de Fajaro: Porto Rico; Hispaniola; Bahamas. PEDILANTHUS LATIFOLIUS Millsp. & Britton, sp. nov. Shrubby, about 6 feet high, the young branches zig-zag, puberulent. Leaves ovate to ovate-orbicular, 4.5 inches long or less, very nearly sessile, dull-green, acute at the apex, roundish or subcordate at the base, very inconspicuously veined, glabrous, the midrib elevated but not keeled beneath. Inflorescence termi- nal, cymose, puberulent, bracteate; bracts lanceolate, acute, 3.5-4x2 lin., some- what exceeding the peduncles; involucre about 10x4.5 lin., glabrous without and within, tube narrow anteriorly, main lobes lanceolate-oblong, rounded obtuse, ciliate at the apex, the accessory lobes equal or nearly so connivent with the main lobes to near the ciliate apices, fifth lobe elongate-ligulate, truncate ciliate, somewhat shorter than the accessory lobes and nearly closing the superior fissure of the tube; appendix large, strongly saccate, about one-third the length of the tube, split for half its length into two sarcous, ligulate slightly grooved and emarginate lobes; glands 4, of two sorts: the upper pair reniform at the summit of a broadly triangular stipe which is connivent with the surface of the appendix, anterior margins free and sharp; lower pair about one-half the size of the upper, discoid, peltate on a very short, free pedicel. Male pedicels numerous, glabrous; female pedicel glabrous ; ovary glabrous ; style 3-lobed at the apex, the stigmatic branches bifid. Fruit unknown. Castle Point, Bermuda (Brown & Britton, 820, type). Near Bath, Jamaica (Britton, 3491). Baracoa, Cuba (Bemis). Sanchez, Santo Domingo (Rose, Fitch & Russell, 4397). Mona Island (Britton, Cowell & Hess, 1786). Perhaps indigenous at the Santo Domingo locality cited; at all the others an evident escape from cultivation, or in gardens. METOPIUM TOXIFERUM (L.) Krug & Urban Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. COMOCLADIA DODONAEA (L.) Urban Frequent on the plateau: Porto Rico; Hispaniola. RHACOMA CROSSOPETALUM L. Frequent on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas ; Curacao. GYMINDA LATIFOLIA (Sw.) Urban Occasional on the coastal plain: Porto Rico; Hispaniola; Bahamas. 44 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 SOHAEFFERIA FRUTESCENS Jacq. Common on the coastal plain: Porto Rico; Hispaniola; Bahamas. CARDIOSPERMUM MICROCARPUM HBK. Frequent on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. HYPELATE TRIFOLIATA Sw. Coastal plain near Sardinera: Porto Rico; Hispaniola; Bahamas. EXOTHEA PANICULATA (Juss.) Radlk. Base of limestone cliffs, Sardinera: Porto Rico; Hispaniola; Bahamas. DODONAEA EHRENBERGII Schl. Common on the coastal plain and on the plateau: Hispaniola; Bahamas. KRUGIODENDRON FERREUM (Vahl) Urban Occasional on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. REYNOSIA UNC1NATA Urban Frequent on the plateau: Porto Rico. SARCOMPIIALUS TAYLORI Brit ton Occasional on the coastal plain: Bahamas, COLUBRINA COLUBRINA (K) Millsp. Occasional along the base of the cliffs, coastal plain: Porto Rico; Hispaniola; Bahamas. CISSUS TRIFOLIATA L. Coastal thickets: Porto Rico; Hispaniola; Bahamas; Aruba. CORCHORUS SILIQUOSUS L. Occasional on the coastal plain: Porto Rico; Hispaniola; Bahamas. CORCHORUS HIRSUTI S L. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas ; Curacao. ABUTILON UMBELLATUM (L.) Sweet Frequent on the coastal plain: Porto Rico; Hispaniola; Curacao. GAYOIDES CRISPUM (L.) Small Occasional on the coastal plain: Porto Rico; Hispaniola; Bahamas. MALVASTRUM SPICATUM (L.) A. Gray Cultivated ground, coastal plain: Porto Rico; Hispaniola; Curacao. SIDA SPiNOSA L. Cultivated ground, coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. SIDA GLABRA Mill. {B. ulmifolia Cav.) Frequent on the coastal plain: Porto Rico; Hispaniola. SIDA PROCUMBENS Sw. Occasional on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. SIDA ACUMINATA DC. Frequent on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. BASTARDIA VISCOSA (L.) HBK. Occasional on the coastal plain: Porto Rico; Hispaniola; Bahamas; recorded from Curacao. MALACHRA CAPITATA L. Occasional in cultivated ground, coastal plain: Porto Rico; Hispanioja. 1915] BRITTON VEGETATION OF MONA ISLAND 45 PARITIUM TILIACEUM (L.) Juss. Border of a swamp, Sardinera: Porto Rico; Hispaniola; Bahamas. GOSSYPIUM BARBADENSE L. Spontaneous after cultivation on the coastal plain. Apparently not native. MELOCHIA TOMENTOSA L. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas; Curacao. WALTHERIA AMERICANA L. Occasional on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas ; Cura cao. AYENIA PUSILLA L. Frequent on the coastal plain: Porto Rico; Hispaniola; Bahamas. HELICTERES JAMAICENSIS Jacq. Frequent on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. CLUSIA ROSEA Jacq. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. CANELLA WINTERANA (L.) Gaertn. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. TURNERA DIFFUSA Willd. Occasional on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. PASSIFLORA SUBEROSA L. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas ; Curacao. PASSIFLORA FOETIDA L. Sandy beach, Playa de Fajaro: Porto Rico; Hispaniola; Bahamas; Curacao. CARICA PAPAYA L. Common on the coastal plain about Sardinera, apparently established after cultivation. A race with small globose fruits. Original home unknown. HARRISIA PORTORICENSIS Britton Common on the talus and on the plateau: Porto Rico. CEPHALOCEREUS ROYENI (L.) Britton & Rose Common on the plateau: Porto Rico [St. Thomas to Antigua]. CACTUS INTORTUS Mill. (Melocactus portoricensis Suringar.) Common on the plateau: Porto Rico [St. Thomas to Antigua]. CORYPHANTHA NIVOSA (Link) Britton. (Mamillaria nivosa Link.) Very abundant on the plateau: Culebra [St. Thomas to Tortola; Antigua]; Bahamas. OPUNTIA CATACANTHA Link & Otto Common on the plateau; occasional on the coastal plain: Porto Rico [St. Thomas to Antigua]. OPUNTIA TAYLORI Britton Top of cliff near Sardinera: Santo Domingo; Culebra [St. Thomas to Tortola] . OPUNTIA DILLENII (Ker.) Haw. Common on the coastal plain and on the plateau. Not collected: Porto Rico; Hispaniola; Bahamas. Vol. 2 46 ANNALS OF THE MISSOURI BOTANICAL GARDEN TERMINALIA CATAPPA L. Occasional on coastal sands: Porto Rico; Hispaniola; [spontaneous after cultivation in the Bahamas]. CONOCARPUS ERECTA L. Occasional in coastal sands: Porto Rico; Hispaniola; Bahamas; Curacao. BUCIDA BUCERAS L. Coastal woods, Ubero: Porto Rico; Hispaniola; Bahamas. LAGUNCULARIA RACEMOSA (L.) Gacrtn. Borders of marshes, coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. CALYPTRANTHES PALLENS (Poir.) Griseb. Base of dill's, Ubero: Porto Rico ( ?) ; Hispaniola; Bahamas. EUGENIA BUX1FOLIA (Sw.) Willd. Common on the const al plain and on the plateau: Porto Rico; Hispaniola; Bahamas. EUGENIA AXILLARIS (Sw.) Willd. Frequent or occasional on the coastal plain, at the base of cliffs and on the plateau: Porto Rico; Hispaniola; Bahamas. EUGENIA RHOMB FA (Berg.) King. & Urban Coastal plain between Sardineia and Ubero: Porto Rico; Hispaniola; Bahamas. ANAMOMIS FRAGRANS (Sw.) Griseb. Occasional on the coastal plain: Porto Rico; Hispaniola. Recorded from the Bahamas. JACQUINIA BARBASCO (Loefl.) Mez. Common in coastal thickets and occasional on the coastal plain: Porto Rico; Hispaniola; Curacao. ? DIPIIOLIS Coastal plain, Sard intra. A tree about 12 m. high, in foliage only. BUMELIA OBOVATA (Lam.) DC. Frequent on the coastal plain. Not in flower or fruit at the time of our visit: Porto Rico; Hispaniola; Curacao. PLUMIERA OBTUSA L. Common on the coastal plain and on the plateau: Hispaniola; Bahamas. RAUWOLFIA TETRAIMIYLLA L. {R. nitida dacq.) Frequent on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. ECHITES AGGLUTINATA Jacq. Occasional on the coastal plain and on the plateau: Porto Rico; Hispaniola. URECHITES LUTE A (L.) Britton Occasional on the coastal plain: Porto Rico; Hispaniola; Bahamas. METASTELMA (undetermined) Coastal rocks, Ubero. METASTELMA (undetermined) Occasional on the coastal plain and on the plateau. EVOLVULUS GLABER Spreng. Moist soil, coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. 1915] BRITTON VEGETATION OF MONA ISLAND 47 JACQUEMONTIA JAMAICENSIS (Jacq.) Hall. f. Occasional on coastal sands: Porto Rico; Hispaniola; Bahamas. JACQUEMONTIA PENTANTHA (Jacq.) D. Don Frequent on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas; Curacao. OPERCULINA AEGYPTIA (L.) House Cultivated ground, coastal plain: Porto Rico; Hispaniola; Curacao. ? EXOGONIUM MICRO DACTYLUM (Griseb.) House Occasional on the plateau. Specimen insufficient for certain determination. IPOMOEA PES-CAPRAE (L.) Roth. Common on coastal sands: Porto Rico; Hispaniola; Bahamas; Curacao. IPOMOEA TRILOBA L. Frequent in cultivated ground on the coastal plain: Porto Rico; Bahamas. CALONYCTION GRANDIFLORUM (Jacq.) Choisy. (Ipomoea tuba G. Don.) Frequent in coastal thickets: Porto Rico; Hispaniola; Bahamas; Curacao. VARRONIA GLOBOSA Jacq. Occasional on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. BOURRERIA SUCCULENTA Jacq. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Curacao. MALLOTONIA GNAPHALODES (L.) Britton.i (Tournefortia gnapha- lodes R. Br.) Common on coastal sands: Porto Rico; Hispaniola; Bahamas; Curacao. TOURNEFORTIA HIRSUTISSIMA L. Base of limestone cliffs, Sardinera: Porto Rico; Hispaniola. TOURNEFORTIA MICROPHYLLA Bert. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola. HELIOTROPIUM CRISPIFLORUM Urban Moist soil, coastal plain: Porto Rico. Closely resembles the Porto Rico plant but is lower and with shorter internodes; no ilowering specimens were obtained. HELIOTROPIUM PARVIFLORUM L. Frequent on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. LANTANA SCABR1DA Ait. Collected by Professor Stevens, not found by us: Porto Rico; Hispaniola. Apparently specifically distinct from L. Camara L. LANTANA INVOLUCRATA L. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas ; Curacao. VALERIANODES JAMAICENSIS (L.) Medic Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas; Curacao. VALERIANODES STRIGOSA (Vahl) Kuntze Frequent on the coastal plain and on the plateau: Porto Rico; Hispaniola. iMallotonia (Griseb.) Britton, gen. nov. Tournefortia Section Mallotonia Griseb. Fl. Brit. W. I. 483. 1861. Type species: Tournefortia gnaphalodes (L.) R. Br. [Vol. 2 48 ANNALS OF THE MISSOURI BOTANICAL GARDEN SALVIA SEROTINA L. (flf. micrantha Vahl) Frequent on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. HYPTIS PECTINATA (L.) Poit. Cultivated ground on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. SOLANUM NIGRUM L. (S. americanum Mill.) Cultivated ground, Sardinera: Porto Rico; Hispaniola; Bahamas; Curacao. SOLANUM VERBASCIFOLIUM L. Occasional at the bases of cliffs and on the coastal plain: Porto Rico; Hispaniola; Bahamas. BRAM1A MONNIERIA (L.) Drake. (Herpestis Monniera HBK.) Border of a pool, Sardinera: Porto Rico; Hispaniola; Bahamas. CAPRARIA BIFLORA L. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas; Curacao. SCOP ARIA DULCIS L. In moist soil on the coastal plain: Porto Rico; Hispaniola; Bahamas. TABEBUIA HETEROPHYLLA (DC.) Britton. (Raputia (?) heterophylla DC; Tabebuia triphj/Ila DC, not Bujnonia triphylla L.) Frequent on the coastal plain and on the plateau. Leaves 1-foliolate to 5-foliolate: Porto Rico. TABEBUIA LUCIDA Britton, sp. nov. A tree up to 5 m. high. Leaves 3-5-foliolate; petioles slender, lepidote, 6 cm. long or less; petiolules of the larger, upper leaflets slender, lepidote, 8-20 mm. long; lower leaflets sessile or nearly so; lea Nets thin-coriaceous, narrowly oblon" or oblong-oblanceolate, 5-10 cm. long, 1-3 cm. wide, shining, reticulate-veined and lepidote on both sides, rather abruptly acute or obtusish at the apex, narrowed or obtuse at the base; flowers clustered; pedicels lepidote; calyx about 14 mm. long, 2-lipped; corolla pink, glabrous, about 5 cm. long, its cylindric tube 5-6 mm! long, its narrowly campanulate throat about 3 cm. long, its limb about 1.5 cm. long, the lobes nearly entire. Limestone cliffs, Sardinera, Mona Island, Porto Rico (Britton, Co well and Hess 168(1 ). ' SESAMUM ORIENTALK L. Cultivated ground, coastal plain. Native of the East Indies. BLECHUM BROWNEI Juss. Shaded rocks, Sardinera: Porto Rico; Hispaniola; Bahamas. JUSTICIA PERIPLOCIFOLIA Jacq. Occasional on the coastal plain, a narrow-leaved race: Porto Rico; His- paniola. JUSTICIA PECTORAL] K Jacq. Border of pool, Sardinera: Porto Rico; Hispaniola. PLANTAGO MAJOR L. Cultivated ground, coastal plain. Not collected. Native of the Old World. EXOSTEMA CARIBAEUM (Jacq.) R. & S. Frequent on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. RANDIA ACULEATA L. Common on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas; Curacao. 1915] BRITTON VEGETATION OF MONA ISLAND 49 GUETTARDA ELLIPTICA Sw. Occasional on the coastal plain: Porto Rico; Hispaniola; Bahamas. STENOSTOMUM ACUTATUM DC. Frequent on the coastal plain and on the plateau: Porto Rico; Curacao. ERITHALIS FRUTICOSA L. Common on sand dunes, on the coastal plain and occasional on the plateau: Porto Rico; Hispaniola; Bahamas; Curacao. CHIOCOCCA ALBA (L.) Hitchc. Occasional on the coastal plain and on the plateau: Porto Rico; Hispaniola; Bahamas. STRUMPFIA MARITIMA Jacq. Limestone plateau near Ubero, frequent: Porto Rico; Hispaniola; Bahamas; Curacao. PSYCHOTRIA UNDATA Jacq. Occasional on the coastal plain: Porto Rico; Hispaniola; Bahamas. ERNODEA LITTORALIS Sw. Common on coastal sands: Porto Rico; Hispaniola; Bahamas; Bonaire. SPERMACOCE TENUIOR L. Frequent on the coastal plain: Porto Rico; Hispaniola; Bahamas; Curacao. CUCUMIS ANGURIA L. Cultivated ground, Sardinera: Porto Rico; Hispaniola; Curacao. EUPATORIUM ODORATUM L. Common on the coastal plain: Porto Rico; Hispaniola; Bahamas. EUPATORIUM ATRIPL1C1 FOLIUM Lam. Coastal rocks, Sardinera: Porto Rico; recorded from Hispaniola and from the Bahamas. LEPTILON PUSILLUM (Nutt.) Britton Common in waste and cultivated grounds, coastal plain: Porto Rico; His- paniola ( ?) ; Bahamas. LEPTILON BONARIENSE (L.) Small Cultivated ground, Sardinera: Porto Rico; Hispaniola. PLUCHEA PURPURASCENS (Sw.) DC. Borders of marshes, coastal plain: Porto Rico; Hispaniola; Bahamas. BORRICHIA ARBORESCENS (L.) DC. Occasional on coastal rocks: Porto Rico; Hispaniola; Bahamas. WEDELIA PARVIFLORA L. C. Rich Common on the coastal plain : Porto Rico. ELEUTHERANTHERA RUDERALIS (Sw.) Sch. Bip. Cultivated ground, coastal plain: Porto Rico; Hispaniola. Erroneously recorded from the Bahamas. BIDENS CYNAPIIFOLIA HBK. Collected by Professor Stevens, not found by us: Porto Rico; Hispaniola; Bahamas; Curacao. PTERIDOPHYTA (Determined by Miss Margaret Slosson) ADIANTUM FRAGILE Sw. Limestone cliff, Sardinera: Porto Rico; Hispaniola. vSO ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol ACROSTICHUM AUREUM L. Border of pool near Sardinera. Determined from barren leaf specimen: Porto Rico; Hispaniola; Bahamas; Curacao. CYCLOPELTIS SEMKORDATA (Sw.) J. Smith Shaded limestone rocks, Sardinera: Porto Rico; Hispaniola. MUSCI (Determined by Elizabeth G. Britton and R. S. Williams) TUUIDIUM INVOLVES (Hedw.) Mitt. On dead wood and shaded rocks: Porto Rico; Hispaniola. TORTULA AGRARIA Sw. On the ground near Sardinera: Porto Rico; Hispaniola; Bahamas. HYOPHILA GUADELUPENSIS Broth. Wet soil on the coastal plain between Sardinera and Ubero: Guadeloupe; Montserrat. BRYUM MICRODEC1 TOKENS E. G. Britton Wet soil on the coastal plain between Sardinera and Ubero: St. Thomas. CALYMPERES RICHARDI C. Muell. On tree trunks, base of cliff, Sardinera: Porto Rico; Hispaniola; Bahamas. CALYMPERES (an apparently undescribed species) On Bourreria, Ubero; Hispaniola. HEPATICAE JUNGERMANNIACEAE (Determined by Professor A. W. Evans) BRACHIOLEJEUNEA HAHAMENSIS Evans On limestone, Ubero; on trunk of (hjmnanth* s, Sardinera: Bahamas. MASTIGOLEJEUNEA AURICULATA (Wils. & Hook.) Schififn. On shaded limestone and on dead wood, Sardinera: Porto Rico; Bahamas LEJEUNEA (barren and undeterminable) On shaded limestone, bark and dead wood. FRULLANIA SQUARROSA (R. B. & U.) Dumort. On trunks and logs on the coastal plain: Porto Rico; Bahamas FRULLANIA (barren and undeterminable) On dead wood, Sardinera. RICCIACEAE ( Coni ributed by Dr. Marshall Avery Howe) RICCIA BRITTONII, sp. nov. Thallus simple or once dichotomous, forming irregularly gregarious patches, oblong-ovate, linguiform, or obovate, 2-5 mm. x 1-2 mm., subacute or obtuse, con- spicuously alveolate-reticulate and light green above, with a scarious-albescent border 80-175 fi wide, concolorous or very commonly brownish laterally and ven- trally; median sulcus deep and acute except in older parts; ventral scales small, inconspicuous, hyaline, rarely exceeding the thin membranous ascending thallus- margins; transverse sections mostly 1.5-2.0 times as wide as high, the ventral outlines semi-orbicular in younger parts, becoming flattened in the older; cells of the primary dorsal epidermis cylindric dome-shaped or subhemispheric, soon col- lapsing, leaving shallow slightly indurated more or less persistent cup-like vestiges; monoecious; antheridial ostioles scarcely derated; spores brown, be- coming subopaque, soon exposed, 100-145 fx in maximum diameter, rather ob- 1915] BRITTON VEGETATION OF MONA ISLAND 51 scurely or sometimes distinctly angled, often flattened, destitute of wing-margins, almost uniformly areolate over the whole surface, with age showing in profile obtuse or truncate papillae 3-5 fi long, areolae mostly 10-18 fi wide. On wet, sunny soil, accompanied by R. violacea, between Sardinera and Ubero, Mona Island, February, 1914, Britton, Cowell, & Hess, 17Jf9a. Riccia Brittonii exhibits certain points of contact with Riccia sorocarpa Bisch. and R. dictyospora M. A. Howe. 1 It is close to R. sorocarpa in vegetative char- acters, though differing in the wider, more pronounced, scarious-albescent thallus- margins and slightly in the character of the epidermis, but it departs widely from this species in the spores, which are much larger (100-145 \i vs. 70-90 /x, max. diam.), are destitute of wing-margins, and commonly have the areolae of the inner faces almost as well and regularly developed as those of the outer face. From Riccia dictyospora, the species differs in the less elongate thallus (2-5 mm. vs. 4-10 mm.), the albescent instead of dark purple thallus-margins and scales, the more semicircular and less parabolic outlines of transverse sections of the thallus, and in the larger spores (100-145 fi vs. 95-1 1G /x, max. diam.), with larger areolae (10-18 a vs. 8-12 a. RICCIA VIOLACEA, sp. nov. 5-4 long, the main segments oblong-obovate or linguiform, 0.65-1.15 mm. broad, rather obscurely and finely areolate and dark green above, dark violet or blackish at margins and on sides, this color encroaching on the surface here and there, es- pecially in the older parts and at the sinuses; median sulcus shallow or obsolete except at apex; ventral scales very short or rudimentary, dark violet, rarely over- lapping, commonly divided into a series of small irregular often tooth-like lamellae, each consisting of only a few cells; transverse sections plano-convex, somewhat flattened-semiorbicular, or occasionally biconvex, 1.5-2.0 times as wide as high; the margins obtuse or rounded, bearing especially toward the apex numerous or occasional violet or sometimes hyaline conic or subcylindric acute or obtuse papillae 30-110 fi long and 25-45 fi broad at base; cells of the primary dorsal epidermis subhemispheric or mammiform, soon collapsing and leaving inconspicu- ous vestigia; remaining parts unknown. On wet, sunny soil, accompanied by Riccia Brittonii, between Sardinera and Ubero, Mona Island, February, 1914, Britton, Cowell, & Hess, 1749b. In size, habit, and color, R. violacea is somewhat suggestive of R. nigrella DC., but the thallus has papillae or very short cilia at the margins, which are wanting in R. nigrella, the scales are much smaller, more rudimentary and more divided than in R. nigrella, and the cells of the primary epidermis are much less persistent. Its nearest affinity is doubtless with R. atromarginata Levier, which is known from Sicily, Sardinia, and Greece; from this it appears to differ (if one may judge from the descriptions alone) in the obtuse thallus-margins, the very short, rudimentary, divided, rarely overlapping scales, and the commonly violet papillae which are confined to the margins and sides while in R. atromarginata the hyaline incurved "pili" are said to cover also the anterior dorsal surface. LICHENES (Determined by Professor Lincoln W. Riddle) ARTHOPYRENIA On Coccolobis obtusifolia, Ubero. PYRENULA On bark, Sardinera. MELANOTIIECA CRUENTA (Mont.) Muell. Arg. On Oymnanthes, Sardinera. TRYPETHELIUM ELUTERIAE Spreng. On Pithecolobium, Sardinera, and on Coccolobis obtusifolia, Ubero. iBull. Torr. Bot. Club 28: 163. 1901. [Vol. 2 52 ANNALS OF THE MISSOURI BOTANICAL GARDEN TRYPETHELIUM MASTOIDEUM Ach. On Pithecolobium, Sardinera. TRYPETHELIUM OC1 1 ROLEUCUM Nyl. On Zanthoxylum, between Sardinera and Ubero. OPEGRAPHA On Ficus, Sardinera; on Calyptranthes, Ubero. GRAPHIS AFZELII Ach. On Zanthoxylum, between Sardinera and Ubero; on Pithecolobium, Sardinera. GRAPHIS Collected by Professor Stevens. CHIODECTON On Plumiera, Sardinera. LEPTOTREMA On dead wood, Sardinera. CLADONIA FIMBRTATA var. CONIOCRAEA (Floerke) Wainio On dead log, Sardinera. OMPHALARIA LINGULATA Tuck. On limestone, Sardinera. OMPHALARIA POLYGLOSSA Nyl. On exposed limestone, Ubero. OMPHALARIA On limestone, Ubero. COLL EM A On limestone rocks, Sardinera. LEPTOGIUM (sterile and indeterminable) On Torrubia, Sardinera. PARMELIA TINCTORUM Despv. On a tree trunk. PARMELIA SULPHURATA Nees and Flot. On a dead log, Sardinera. RAMALINA MONTAGNEI De Not. On a twig, Sardinera. Collected also by Professor Stevens. RAMALINA COMPLANATA (Sw.) Ach. On a twig, Sardinera. PYXINE P1CTA (Sw.) Tuck. On Pithecolobium, Sardinera; on Zanthoxylum, between Sardinera and Ubero. PHYSCIA SPECIOSA (Wulf.) Nyl. (A small form) On Ficus, Sardinera. PHYSCIA ALBA Fee On Calyptranthes, Ubero; also, not typical, on Torrubia, Sardinera. The collection also contains a sterile plant near Omphalaria Wrightii Tuck., from wet, sunny soil between Sardinera and 1915] BRITTON VEGETATION OF MONA ISLAND 53 Ubero, a sterile species of the Dermatocarpaceae growing on limestone at Ubero, and three other sterile and undetermin- able specimens. BASIDIOMYCETES (Determined by Dr. W. A. Murrill) LENTINUS CRINITUS (L.) Fries On dead wood, Ubero: Porto Rico; Bahamas. SCHIZOPHYLLUM ALNEUM (L.) Schroet. Frequent on dead wood: Forto Rico; Bahamas. DAEDALEA AMANITOIDES Beauv. On dead wood, Ubero: Porto Rico; Bahamas. INONOTUS CORROSUS Murr. On dead wood, Sardinera: Porto Rico; Bahamas. PYROPOLYPORUS DEPENDENS Murr. On dead wood: Porto Rico; Bahamas. POGONOMYCES HYDNOIDES (Sw.) Murr. On dead wood: Porto Rico; Bahamas. PYCNOPORUS SANGUINEUS (L.) Murr. Frequent on dead wood at base of escarpment: Porto Rico; Bahamas. ■ CORIOLOPSIS RIGIDA (Berk. & Mont.) Murr. On dead wood, Sardinera: Porto Rico; Bahamas. CORIOLUS PINSITUS (Fries) Pat. On dead wood: Porto Rico; Bahamas. XYLARIA On dead log, Ubero. UREDINALES (Determined by Professor J. C. Arthur) COLEOSPORIUM PLUMIERAE Pat. On Plumiera obtusa. KUEHNEOLA GOSSYPII (Lagerh.) Arth. On Gossypium barbadense. PUCCINIA CENCHRI Dietr. & Holw. On Cenchrus. PUCCINIA CRASSIPES B. & C. On Ipomoea triloba L. PUCCINIA EUPHORBIAE P. Henn. On Aklenea petiolaris (Sims) Millsp. PUCCINIA INFLATA Arth. On Stigmaphyllon lingulatum (Poir. ) Small PUCCINIA LATERITIA B. & C. On Ernodca littoralis Sw. [Vol. 2 54 ANNALS OF THE MISSOURI BOTANICAL GARDEN PUCCINIA URBAN1ANA P. Henn. On Valerianodes strigosa (Vahl) Kuntze UREDO BIOCELLATA Arth. On Pluchea purpurascens (Sw. ) Kuntze UREDO CAMELIAE Mayor. On Chaetochloa sctosa. Many parasitic fungi collected by Professor Stevens have not yet been determined. ALGA (Determined by Professor N. Wille) SCYTONEMA OCELLATUM Lyngb. Flat limestone plateau, Ubero. Recapitulation Species indicated in the foregoing list 292 Deduct thallophytes (distribution little known) 47 245 Deduct undetermined and doubtfully determined species 12 233 Deduct certainly introduced species 8 225 Deduct endemic species 4 221 a a In common with Porto Rico 211 " Hispaniola 185 Bahamas 155 Curacao 87 . . . . a <. Species other than Endemic Ones and Thallophytes not known on Porto Rico (including Desecheo, Culebra and Vieques) Cenchropsis myosuriodes : Bahamas; Cuba. Domingoa hymenodes: Hispaniola; Cuba. Caesalpinia domingensis : Hispaniola. Guilandina melanosperma : St. Croix. Dodonaea Ehrenbergii : Bahamas; Hispaniola; Cuba. 1915] BRITTON VEGETATION OF MONA ISLAND 55 Sarcomphalus Taylori: Bahamas. Plumiera obtusa: Hispaniola; Bahamas; Cuba. Brachiolejeunea bahamensis: Florida; Bahamas. Hyophila guadelupensis : Guadeloupe; Montserrat Bryum subdecurrens : St. Thomas. [Vol. 2, 1915] 56 ANNALS OF THE MISSOURI BOTANICAL GARDEN Explanation of Plate plate 1 Fig. 1. Escarpment, Mona Island, showing openings of caves. Fig. 2. Part of Mona Island from the ocean, showing escarpments and plateau. Ann. Mo. Bot. Gard., Vol. 2, 1915 Plate 1 Fig. 1 Fig. 2 BRITTON— VEGETATION OF MONA ISLAND COCKAYNE, BOSTON [Vol. 2, 1915] 58 ANNALS OF THE MISSOURI BOTANICAL GARDEN Explanation of Plate PLATE 2 Fig. L Escarpment and tables, Mona Island. Fig. 2. Coastal thicket, Mona Island. THE FLORA OF NORWAY AND ITS IMMIGRATION N. WILLE Professor at the Christiania University The phytogeographical investigations in a country may be carried on in the following three main directions : Floristic phy to geography, or an investigation into the geo- graphical distribution of the plant species. The result of this work should be charts of the distribution in the country of the various species. In a country with such varied condi- tions of life as Norway, this is a very comprehensive and very arduous task, requiring an infinitude of detailed investi- gations in all parts of the country. Ecological phy to geography, which endeavors to find out how and why the different species of plants in various places and under various conditions of life come together in plant- communities. This branch of science, which was founded by Professor E. Warming, must be based upon phytoanatomy and phytophysiology, as the connection between the organi- zation of the vegetable species and their external conditions of life must be investigated. Investigations such as these may yield interesting results in all countries, and are most easily carried on where the conditions of life are uniform over wide areas ; but in a country like Norway, with its varied conditions, they present very great difficulties. Historical phyto geography has for its aim the investiga- tion of the changes that in the course of time have taken place in the vegetation of a country — to find out, for instance, when and whence important species have immigrated, how quickly they have spread, why others, that had formerly been more widely distributed, had a more restricted distribution in a later period, etc., etc. With regard to this last branch of science, the Scandin- avian countries, Denmark, Finland, Norway, and Sweden, present peculiarly favorable conditions ; for there is no doubt that these countries were formerly buried under a continu- Ann. Mo. Bot. Gard., Vol. 2, 1915 (59) 60 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 ous covering of ice, which destroyed all vegetation except perhaps the most hardy. All other species of plants have immigrated subsequently from the neighboring countries, which were not covered with ice during the Glacial Epoch, and could therefore afford a dwelling-place for a more or less abundant flora. In the following pages I shall endeavor to give an account of the results at which historical phytogeography may be said to have arrived as far as Norwav is concerned. Survey of the Distribution of the Norwegian Flora It will first be necessary, however, to give a general ac- count of the most important points regarding the composi- tion and distribution of the Norwegian flora throughout the country. I shall here consider only the vascular plants (about 1,500 species), however, as the distribution of the lower plants is not sufficiently known to enable us to draw definite conclusions. The area of Norway is about 125,000 square miles, stretch- ing from latitude 57° 58' 43" north to latitude 71° 10' 20" north. The conditions for plant life will thus be very differ- ent in the southern and northern parts of the country. But in addition to this, there is a great difference between the climate in the east and that in the west of southern Norway. In the valleys of the East Country, there is a very pronounced inland climate, with hot summers and a winter temperature that falls below — 40 °C, while on the west coast region there is a low summer temperature, but a mean January tempera- ture of sometimes more than 2°C. The most important condition affecting the distribution of plants in Norway is the temperature. In this connection we shall in the first place speak of the lowest winter tempera- ture that the plants can survive. J. Hohnboe ('13) has shown that the distribution of Ilex a qui folium in Norway coincides closely with the January isotherm for 0°C. Herb- aceous plants which die down in the winter may of course be independent of the lowest winter temperature, as they are covered with snow; but they are not entirely independent of 1915] WILLE FLORA OF NORWAY 61 the spring and autumn temperature. Plants are also in a great measure dependent on the height of the temperature in the period of vegetation, which, in Norway, comprises in the main the four months, June, July, August, and September. Fig. 1. Isotherms for January. In this way, the conditions prevailing in Norway are very varied, the July isotherm for Christiania being 17 °C, while for the west coast it is only from 12 to 14° C. A. Helland ('12) has calculated that where the mean sum- mer temperature in Norway is less than 13° C, the fruit [Vol. 2 62 ANNALS OF THE MISSOURI BOTANICAL GARDEN trees yield nothing worth mentioning; and where it is less than 11° C, the cultivation of grain is uncertain. The mini- mum limits of the necessary mean summer heat for the fol- lowing wild Norwegian trees and shrubs appears to be as Fig. 2. Isotherm* for July. follows: for Fagus sylvatica, 13.4°C. ; Quercus pedunculated, 12.6°C. ; Corylus Avellana, Acer platanoides, and Tilia cor- data, 12.5°C. ; Alnus glutinosa and Fraxinus excelsior, 12.4° C. ; Sorbus Aria and Ulmus montana, 11.2°C. ; Picca excelsa and Pinus sylvestris, 8.4°C. ; Alnus incana, Prunus Padus, 1915] WILLE — FLORA OF NORWAY 63 and Sorbus Aucuparia, 7.7°C. ; Populus tremula, 7.6°C. ; Betula odorata, 7.5°C. ; Juniperus communis var. nana, 5.3° C. ; and Betula nana, 4.3°C. As the mean temperature of summer decreases with in- creasing height above sea-level very nearly 0.6° C. per 330 feet, the distribution of plants is greatly influenced by the circumstance that Norway is a mcuntainous country, its highest mountain, Galdhopiggen, being 8,095 feet in height, and thus within the region of perpetual snow. But a pecu- liarity of the Norwegian mountains is that they form broad (as much as sixty-two miles broad}, undulating mountain plateaus, which are intersected by deep or shallow valleys, where there are narrow lakes or small rivers. The edge of these mountain plateaus, in the south of Norway, lies at a height of from 2,950 to 3,280 feet above the sea, so that Picea excelsa and Pinus sylvestris disappear slightly below this height, the edge of the plateaus and the lowest valleys that intersect them being covered with Betula odorata. The great mass of the mountain plateaus, which rise above the birch- limit, is thus treeless. It has been calculated that there are 26,333 square miles of forest land in Norway, of which 73 per cent consists of Picea excelsa and Pinus sylvestris, while the remaining 27 per cent is mainly Betula odorata with a little Betula verru- cosa, Quercus pedunculata, and Q. vessiliflora, and a very little Fagus sylvatica in the south. The vegetation limits are lower not only toward the north, as one would expect, but also towarc. the west, as they are lower near the sea than inland. This will be seen from the following height-limits in feet : Snow-line Birch-limit Pine-limit ft. ft. ft. Gausta in Telemarken (south of Norway) • • 3450 3024-3113 Vos (west of Norway) 3936 3359 1994 Snehaetta, in the Dovre Mountains (central Norway) 5375 3464 2880 Rodo in Helgeland (just within the Arctic Circle) 3280 .... 777 Alten in Finmark (70° N. Lat.) . 3516 1476 777-1023 64 [Vol. 2 ANNALS OF THE MISSOURI BOTANICAL GARDEN The distribution northward and height above sea-level of the various vegetable species, will be dependent mainly upon the temperature during the summer months. The rainfall, which in various other countries plays so important a part as a factor in vegetation, is of less import- ing. 3. The annual rainfall in Norway (in centimeters). — After M. Mohn. ince in Norway, as even on the Dovre , ._. ainfall is smallest (about 300 mm. per annum), there is sufficient occasion, on account of de evaporation, swamps and peat-bogs, where even entirely hydrophilous communities thrive. 1915] WILLE FLORA OF NORWAY 65 It was formerly supposed that the largest rainfall was on the outermost islands off the west coast of Norway, and that this was the cause of the Atlantic vegetation that is found there, with such characteristic plants as Hymenophyllum peltatum, Erica cinerea, Scilla verna, Vicia Orobus, etc. But more recent investigations have shown that the rainfall is greater a little way in from the coast, where the mountains begin. In Hovlandsdal, near the Sogne Fjord, a mean rain- fall has been observed of 3,178 mm., and at Skaanevik, near the Folgefon, 2,945 mm., whereas the outermost islands off Bergen show a rainfall of only 1,300 mm., and off Fiord of 1,900 mm. It is, therefore, clear that the occurrence of the above-mentioned Atlantic plants on the outermost islands is due not to a larger rainfall, but to a milder winter tempera- ture. There are, of course, species of plants that cannot thrive in the great humidity of the West Coast; but as there are also localities with comparatively dry soil, it may be rather the low summer temperature than the large rainfall that pre- vents them from thriving. The importance of the soil for vegetable growth appears to depend, in Norway, mainly upon whether the soil is rich, or deficient, in lime. In addition to its chemical influence, a calcareous subsoil, especially when consisting of calcareous slate or limestone, is of consequence from the fact that it forms a warm soil. In Norway, therefore, most of the southern species are found only in the limestone country surrounding the Skien Fjord and the upper part of the Kris- tiania Fjord. The terrestrial plants of Norway may be divided into five zones, according to the ability of the plants to ascend the mountains and extend northward in their growth, that is to say, according to their dependence on the mean temperature of the summer. These zones are here indicated by the upper limit of a characteristic species of plant. I. THE QUERCUS PEDUNCULATA ZONE In the east of Norway this tree is found as far as Lake Mjosen (60° 45' N.), and in the west up to Nordmore (62° 66 ANNALS OK THE MISSOURI BOTANICAL GARDEN [Vol. 2 55') ; but it is nowhere known to have reached a greater height above sea-level than 1.722 feet. The oak can stand a winter temperature as low as — 33.8° C, but requires a mean summer temperature of 12.6° C It is now comparatively rare, and seems to be decreasing. It occurs in large quantities only on the Silurian and along the lower parts of the coast. A number of deciduous trees that are susceptible to cold have about the same distribution as the oak, both in height and in northward extension. These are: Acer platanoides, Alnus glutinosa, Betula verrucosa, Crataegus Oxyacantha, Fraxinus excelsior, Prunus avium, P. insititia, Pyrus Mains, Sorbus Aria, 8. fennica, Taxus baccata, and Tilia cordata. There are also a number of species of cryptogams. It may on the whole be said that the zone here designated the Oak Zone is that of Norway's most abundant flora. Within the Oak Zone, large districts may in their turn be marked off that possess a characteristic flora, the occurrence of which is especially conditioned by circumstances of tem- perature and soil. 1. The Region of the Silurian Flora. — This is developed in an especially characteristic manner on the calcareous slate along the Langesund Fjord, the west side of the Kristiania Fjord, in Eingerike and Hadeland, and around Lake Mjosen. In some of these districts it is fairly cold in the winter, but very hot in the summer; 1 and as the soil is calcareous and warm, a xerophilous steppe-flora, with its characteristic Labiatae, Boragineae, and Centaurea species, and thistles, such as Carlina vulgaris, Carduus acanthoides, etc. — species which also occur in the steppe-regions of South Russia, can thrive well on southern slopes. For the rest, the flora is rich in characteristic species, e.g., Artemisia campestris, Brachypodium pinnatum, Carex prae- cox, Cephalanthera rubra, Cirsium acaule, Fragaria collina, Libanotis montana, Ononis campestris, Phleum phalaroides, 1 In Kriatiania, the 30-yeara' average minimum atmospheric temperature for the month of January in — 16.5°C, and the average maximum for the mouth of June -|-28.9 C. 1915] WILLE FLORA OF NORWAY 67 Spiraea Filipendula, Thymus Chamaedrys, Trifolium mon- tanum, Veronica spicata, etc. Where the soil is deep and not too dry, the above-mentioned deciduous trees that are susceptible to cold form forests or copses, intermingled with Corylus Avellana, Prunus spinosa, species of Rosa and Rubus, and a luxuriant ground vegeta- tion, among which are several orchids. A few of these trees and the more hardy species of the Silurian flora, such as Origanum vulgare and others, may, like an advance-guard, overstep the boundaries of the Silurian regions, but then they generally occur in warm localities, in talus at the foot of cliffs, or in steep slopes that face south- ward, even high up the sides of the valleys, or in the upper parts of the West Country fjords. But the number of species diminishes with increasing dis- tance from the lowland Silurian regions, and there are only a few species that have advanced as far as north of the Dovre Mountains. 2. The Region of Fagus sylvatica. — This region is situated along the southeast coast of Norway, from the Swedish border to Grimstad, where it extends as far north as Holmestrand. There is a small beech-wood a little to the north of Bergen, but this is a solitary instance, and has nothing to do with the real distribution area of the beech. The beech is purely a lowland plant, as there is only one place in which it goes to a height of 886 feet above the sea, its usual height being not more than 525 feet. When culti- & u " uv,iu & vated, it can grow almost as far north as Quercus pedunculata, but prefers a rather higher summer temperature (13.4°C.) and thrives best on comparatively warm gravel banks. The beech is one of those plants which has recently ap- peared to spread to new regions ; and there is no doubt that it has not yet nearly reached the limits of distribution to which it will little by little attain, especially along the low land of the south coast. This is due to the fact that it must have immigrated in fairly recent times. The following plants may also be mentioned as occurring chiefly in the region of the beech : Cladium Mariscus, Cor on- [Vol. 2 68 ANNALS OK THE MISSOURI BOTANICAL GARDEN ilia Emerus, Epilobium obscurum, Laserpitium latifolium, Ligustrum vulgare, Luzula nemorosa, Melampyrum cristatum, Rubus corylifolius, R. Lindebergii, Selinum carvifolium, Slum latifolium, Viscum album, Vicia eassubica, V. lathyroides, etc. A few of these have a rather larger distribution than the beech has at present; others, which must have immigrated recently, are found only within quite a small area. The region for the cultivation of wheat in Norway coin- cides in the main with that of the beech, but extends a little farther, namely westward as far as Mandal, and to a height of 1,246 feet above sea-level. 3. The Region of Ilex Aquifolium. — This region is situated a little to the west of that of the beech, and does not have a lower mean temperature for January than 1°C. It extends from Arendal to Christianssund (63° 7' N. Lat.), but does not include the outermost islands on the west coast. A large number of vegetable species occur in this region. As especially characteristic may be mentioned Aeropsis prae- cox, Asplenium Adiantum nigrum, Cardamine hirsuta, Cen- taur ea decipiens, C. nigra, C. pseudophrygia, Cerastium tetrandrum, Chrysosplenium oppositifolium, Circaea lutetiana, Conopodium denudatum, Corydalis clariculata, Cyitosurus cristatus, Digitalis purpurea, Drosera intermedia, Gentiana Pneumonanthe, Geranium columbinum, Hedera Helix, Jler- acleum australe, Hydrocotyle vulgaris, Hypericum pulehrum, Hypochaeris radicata, Juncus squarrosus, Leontodon hispidus, Luzula sylvatica, Lysimachia nemorum, Meum athanumticum, Quercus sessiliflora, Pilularia globulifera, Poly gala dep res- sum, Primula acaulis, Rosa pimpinelli folia, Rumex obtusi- folius, Sagina subulata, Scirpus setaceus, Sedum anglicum, Senecio Jacobaea, Stellaria Ilolostea, Teesdalia nudicaulis, Triticum acutum, T. junceum, and Weingartneria cotiescens. A few of these species, however, can bear a January isotherm that lies a little lower than 1°C. These species, among which are Hedera Helix and Quercus sessiliflora, occur, therefore, also in the beech region in the southeast of Norway, but have their chief distribution in the Ilex Region, and must therefore be assigned to that region. 1915] "VVILLE — FLORA OF NORWAY 69 4. The Region of the West-European Coast Flora. — This includes the outermost islands in the province of Bergen. The characteristic feature of the climatic conditions here, as we have already stated, is not the large rainfall, for this is in reality smaller than in certain parts of the Ilex Region; but it is the extremely mild winter temperature, and a com- paratively low summer temperature. For purposes of comparison we will here give the mean minima for February and the mean maxima for July, for Kristiania, which forms a center for the Silurian flora, Larvik, the center of the beech region, Mandal of the holly, and Utsire of the West-European coast flora. Mean minimum Mean maximum temperature for February temperature for July Kristiania 15.5° C. 28.8° C. Larvik 14.5° C. 25.8° C. Mandal 11.3° C. 24.8° C. Utsire 5.7° C. 19.9° C. On these outermost islands in the province of Bergen, the mean temperature for January is 2°C. Among the plant species that are especially characteristic of this region may be mentioned Asplenium marinum, Erica cinerea, Hymenophyllum peltatum, Scilla verna, and Vicia Orobus. These species are found in England, and some of them southward along the shore of the Atlantic. II. THE PINUS SYLVESTRIS ZONE In the east of Norway Pinus sylvestris goes right down to the sea, and occurs in many places in the Oak Zone; but in speaking here of a special zone for Pinus sylvestris, we refer to the great continuous forests of Pinus sylvestris and Picea excelsa, which cover wide tracts of country from the upper limit of the Oak Zone to a height of 3,116 feet in the south of Norway, 1,640 in the central part, and 623 in the north. Pinus sylvestris avoids the sea, and is therefore absent from the outermost belt of islands ; but inland it forms, either alone or together with Picea excelsa, a more or less continuous region of distribution below the above-stated height-limits up to latitude 70°N. [Vol. 2 70 ANNALS OK THE Picea excelsa, which immigrated much later than Pinus sylvestris, supplants the latter in favorable localities in the east of Norway; hut in the west its field of distribution is very small, and extends only to latitude 69 °N. Farther north, in the interior of Finmark, small spruce forests do indeed occur, but they are formed of Picea obovata. The forests that are formed of Pinus sylvestris are light, but as they often grow upon dry, poor soil, they are poorly furnished with vegetable species. There may occur scattered specimens of Betula odorata, Alnus incana, Juniperus com- munis, Sorbus Aucuparia, and Populus tremula, ami then a poor ground vegetation of mosses (e.g., Polytrichum juni- perinum), and lichens (e.g., Cladoiiia rangiferina, Cetraria islandica, and Peltigera), among which grow some easily contented higher plants, especially Aira flexuosa, Arctosta- phylos officinalis, Calluna vulgaris, Kmpetrum nigrum, Fes- tuca ovina, Luzula pilosa, Melampyrum sylvaticum, Pteris aquilina, Trientalis europaea, Vaccinium Myrtillus, V. ulig- inosum, and V. Vitis-Idaea. Where this forest, from some cause or other, has been de- stroyed, extensive heath-lands are often formed, consisting chiefly of Calluna vulgaris, among which occur Empetrum nigrum and species of Vaccinium, as also Antennaria dioica, Aira flexuosa, Campanula r otundif olia , Festuca ovina, Nardus stricta, and others. Picea excelsa forms forests on more fertile soil; but as they are very dense and dark, other trees have difficulty in forcing an entrance, and even the ground vegetation is as a rule very poor, owing to the want of light. A thick carpet of mosses (especially Hylocovtium splendens) covers the ground, and the only plants that thrive are fungi, Polystichum spinulosum and some other ferns, JAnnaea borealis, Milium effusum, Oxalis Acetosella, Pyrola uniflora, and others. Where the forests of Picea are less dense, or whore Pinus sylvestris grows upon a more fertile soil, these conifers may be mingled with various deciduous trees, and in the lower districts even with less hardy deciduous trees, which other- wise belong to the Oak Zone. The ground vegetation in such 1915] WILLE FLORA OF NORWAY 71 places is also much more abundant, and the ordinary lowland flora may be found fairly well represented. Almost all cultivated land in Norway lies in the Oak and Pine Zones. Rye and oats ripen up to latitude 69°N., barley even up to 70 °N. — in the south it can be grown up to a height of 2,066 feet above the sea. The potato is cultivated rather farther north and a little higher above sea-level than barley. Side by side with the growing of grain is that of forage plants, of which the most important species are Trifolium vratense and Phleum vratense. III. THE BETULA ODORATA ZONE Betula odorata also occurs in the lowlands, and extends farther toward the sea than Pinus sylvestris, but by its zone, as here defined, is meant the region above the height limit of Pinus sylvestris upon the mountains and north of its distri- bution. In the very south of Norway, Betula odorata goes up to about 3,600 feet above the sea, and northward as far as latitude 71° 10' N. Thus beyond the Birch Zone there is only the northeastern part of Finmark and the highest mountain regions. In the south of Norway the great proportion of the so-called "saeters" lies in the Birch Zone, as this tree generally oc- cupies the margin of the mountain wastes, and fills the little valleys that intersect them with a short-stemmed forest of Betula odorata subsp. alpigena. Side by side with this mountain form of birch, there may also grow Alnus incana, Populus tremula, Prunus Padus and Sorbus Aucuparia. The ground vegetation will be somewhat variable according to the degree of moisture in the soil. On dry gravelly slopes, especially if they face the south, the following species of higher plants are generally found in addition to a few species of lichens, such as Cetraria island- ica, Stereocaulon, etc. : Arctostaphylos officinalis, Agrostis fl A. vulgaris var. pubescens, Antennaria dioica, Anthoxanthum odoratum Astragalus alpinus, Botrychium Lunaria, Betula nana, Call una vulgaris, some species of Car ex, Empetrum nigrum [Vol. 2 72 ANNALS OF THE MISSOURI BOTANICAL GARDEN Euphrasia officinalis, Festuca ovina, Gnaphalium norvegicum, Juniperus communis, Lotus corniculatus, Luzula campestris, L. pilosa, Maianthemum bifolium, Melampyrum sylvaticum, Nardus stricta, Pedicularis Oederi, Peristylis viridis, Phleum alpinum, Poa alpina, Pyrola minor, Rhinanthus minor, Soli- dago Virgaurea, Trientalis europaea, Vaccinium Myrtillus, V. uliginosum, V. Vitis-Idaea, and Vicia Cracca. Where the soil is deeper and damper, and along streams and in shady places, Salix glauca, S. hastata, S. lanata, 8. lap- ponum, 8. Myrsinites and their hybrids make their appear- ance. The vegetation here is more luxuriant, as in addition to most of the above-named, the following species are found: Aconitum septentrionale, Agrostis rubra, Alchemilla vul- garis var. alpestris, Aira alpina, A. caespitosa, Bartschia alpina, species of Car ex, Equisetum hiemale, Geranium sylva- ticum, Gymnadenia conopea, Monlia font ana, Mulgedium alpinum, Myosotis sylvatica, Orchis maculata, Polygonum viviparum, Pinguicula vulgaris, Polemonium caeruleum, Ran- unculus platanifolius, Rumex Acetosa, Saussurea aljtina, Selaginella spinulosa, Soyera paludosa, Spiraea Ulmaria, Viola biflora, and others. Many of these species occur right down to sea-level, some also higher up in the next zone; but as they are always found in the Birch Zone and have their most abundant development there, it is best to refer them to that zone. r> IV. 'HIE ZONK OF DWARF WILLOWS This zone occupies the northeast part of the Yarai peninsula in Finmark and the mountains above the birch limit, up to a height which, in the southernmost point, may be put at 4,133 feet above the sea. It is thus only the tops of the highest mountains which rise like islands above this zone. The mean summer temperature here will be from 8.5 to 4.3 °C, according to the height and situation in higher tudes. The composition of °reatry !-> according to the moisture conditions of the soil, which in their turn to some extent depend on exposure to the sun, south slopes being dry, north slopes damp. 1915] WILLE FLORA OF NORWAY 73 On the drier tracts there are low copses of Betula nana and Juniperus nana, with a ground vegetation of mosses and lichens and a poor selection of mountain plants, such as An- tennaria alpina, Arctostaphylos alpina, Azalea procumbens, Carex rigida, Hieracium alpinum, Juncus triftdus, Erigeron alpinus, E. uniflorus, Festuca ovina, Gnaphalium supinum, Luzula arcuata, Luzula nivalis, L. spicata, Lycopodium alpi- num, L. Selago, Nardus stricta, Pedicularis lapponica, Poly- gonum viviparum, Rhodiola rosea, Salix herbacea, S. reticu- lata, Trientalis europaea, Vaccinium Myrtillus, V. uliginosum, V. Vitis-Idaea, Viscaria alpina, and others. Where the soil is very poor and the climate during the vegetation period very dry, as on the mountain moorlands in the east of Norway — 'round the lake Faemundsoe, and between the valleys Oesterdal and Gudbrandsdal — there occur great lichen-covered heaths consisting of Cladonia rangi- ferina, Cetraria nivalis, C. cucidlata, Alectoria divergens, and A. nigricans, which give a grayish white appearance to the mountains. Among the masses of lichens there are found only a few very easily satisfied mountain plants such as Festuca ovina, Nardus stricta, Solidago Virgaurea, etc. Where, on the other hand, the soil abounds in lime, and the conditions otherwise are favorable, as in certain places on the Hardanger Plateau in the south, Lorn and Dovre in the center, and several places in the north of Norway, rare mountain plants occur, such as Alsine biflora, A. hirta, Dryas octopetala, Primula scotica, P. stricta, Oxytropis lapponica, Papaver radicatum, Rhododendron lapponicum, Salix polaris, Veronica saxatilis, etc. If the soil, on the contrary, is deep and damp, as in mor- asses and along streams, or where water trickles down the sides of mountains, there is quite a different and more abund- ant vegetation, consisting of mosses with thickets of Salix glauca, 8. lanata, S. lapponum, and S. Myrsinites, often with an undergrowth of Aira alpina, Andromeda hypnoides, Car- damine b ellidif olia , Cerastium trigynum, Eriophorum capi- tatum, E. vaginatum, Juncus biglumis, J. castaneus, J. tri- glumis, Koenigia islandica f Oxyria digyna y Petasites frigida, [VOL. 2 74 ANNALS OF THE MISSOURI BOTANICAL GARDEN Ranunculus glacialis, R. nivalis, R. pygmaeus, Sazifraga aizoides, 8. caespitosa, S. rivularis, S. stellaris, Silene acaulis, Tofieldia borealis, Vahlodea purpurea, Veronica alpina, etc. V. THE LICHEN ZONE This embraces the often stony tracts above the preceding zone, i.e., the highest mountain tops and the ground from which they rise. Rocks and stones are here covered with the blackish yellow Lecidea geographica and other lichens. Where there is a little soil, some hardy mosses grow, and under favorable con- ditions a very few species of higher plants. I may mention, as an illustration, that in 1877, when visit- ing the mountain Haarteigen (5,546 feet) in Hardanger, i.e., in the south of Norway, I noted the following higher plants upon the comparatively flat top of the mountain: Carex rigida, Luzula arcuata, L. spicata, Lycopodium Selago, Poa alpina, Polygonum viviparum, Ranunculus glacialis, and Rhodiola rosea. - As already repeatedly stated, all plant species are not strictly confined to the zone under which they are mentioned as especially characteristic factors. It is very general for species somewhat to overstep the boundaries of their true zone, either upward or downward. Certain species are even found in all zones from the sea to the snow, since they have a remarkable ability of adapting themselves to all kinds of soil and to all kinds of climatic conditions. As instances of such species we may mention Calluna vulgaris, Empetrum nigrum, Eriophorum vaginatum, Festuca ovina, Nardus striata, Polygonum viviparum, and the species of Vaccinium. Another circumstance is that typical mountain plants are sometimes found in the lowlands right down to the sea, e.g., in Jaederen, Alchemilla alpina, Arctostaphylos alpina, Bart- schia alpina, Saxifraga aizoides, and Selaginella spinulosa. Betula nana occurs in the southeast of Norway down to fifty feet above the sea, and Dryas octopetala occurs at Lange- sund and at Varaldso in Hardanger at sea-level. These occur- rences were formerly often explained as relics of a previ- 1915] WILLE FLORA OF NORWAY 75 ous age with a colder climate, but I do not think we need have recourse to such an explanation. In all the steep-sided valleys, typical mountain plants spread downward along streams and rivers, and often appear far below their real habitat. Whether they will remain there depends only upon their ability to compete with lowland plants and to withstand the night frosts in the spring after the snow has melted. I assume, therefore, that the occurrence of the above- mentioned mountain plants in the lowlands is due to a chance carrying of seed to places that were favorable to the welfare of the species, e.g., limestone at Langesund and Varaldso for Dry as octopetala, a peat-bog for Betula nana, and so forth. The Immigration of the Norwegian Flora Geologists have long been agreed that Scandinavia and great parts of adjacent lands have once been covered with one entire ice-cap, as the interior of Greenland is at the present time. By degrees the view obtained that there have really been two such glacial epochs, separated by an inter- mediate warm period, in which the conditions probably more or less resembled those of the present day. During the first, called the Great Glacial Epoch, the ice- cap extended as far as central Germany, over almost the whole of England, over the whole of Finland, and over a great part of northern Russia. It follows that under such conditions, all, or almost all, vegetation must have disap- peared from the Scandinavian peninsula, from Norway and Sweden. I am inclined to believe that in places in Norway, the tops of high mountains rose above the ice-covering, and that a very few species of plants may have survived there; but this is a matter of no interest in the question upon which I shall now endeavor to throw light, namely, the immigration of the flora of Norway after the Last Glacial Period. This was of considerably smaller extent. On the south the ice reached only as far as Mecklenburg, and the ice- boundary then ran obliquely northward up through Jutland in Denmark, of which, therefore, only a part was entirely covered with ice. There can be no doubt that the whole of 76 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 Sweden was covered by this ice-cap, but as regards Norway, the conditions are still a matter of dispute. Some geologists maintain that the ice went right out into the sea on all sides ; others assume that in some parts there was an iceless coast- region, where only here and there great glaciers ran out into the sea. The great majority of the species in the Norwegian flora must, however, have immigrated after the last Glacial Period ; but with regard to their immigration and the conditions under which it took place, various theories have been advanced. The first to take up this question, especially with regard to Sweden, was F. W. Areschoug {'66), who, in 1866, main- tained that the present vegetation of Scandinavia was made up of at least three elements of different period and origin, namely : (1) An arctic vegetation, which immigrated from the east during the latter part of the Glacial Period, and, from its origin, may be called the North Siberian Flora; 2) A northeastern and eastern vegetation, which came into Europe from Siberia after the Glacial Period, but before the immigration of the beech. From its origin, it may be called the Altai Flora; (3) A southeastern and southern vegetation, which came simultaneously with the beech, partly from the Caucasus and the countries 'round the Caspian and Black Seas, partly from the countries of the Mediterranean. This may be called the Caucasian and Mediterranean Flora. Areschoug also pointed out that a number of arctic species in the north German and south Swedish lowlands must be regarded as relics of the vegetation of the high north, which, after the melting of the ice-cap, withdrew toward the north or up into the mountains. This view received strong support in the discovery by A. G. Nathorst (71) in 1870, in the fresh- water clays of the south of Sweden, of remains of typical arctic plants which do not grow there now, but only very much farther north, namely, Betula nana, Dryas octopetala, Salix herbacea, S. polaris, and S. reticulata. 1915] WILLE — FLORA OF NORWAY 77 In 1875, Axel Blytt (76) first brought forward his well- known theory on the immigration of the flora of Norway during alternate wet and dry periods. According to Blytt 's theory, the wild plants of Norway should be arranged in the following six groups: (1) the arctic (the mountain flora); (2) the subarctic (the vegetation of mountain and wooded slopes), which is more frequent in the arctic than in the more southern, lower regions; (3) the boreal (the vegetation of the rocky slopes covered with foliage trees), which has its widest distribution in the low land, but not the coast districts; (4) the Atlantic (Bergen coast vegetation), with distribution in the coast district, especially between Stavanger and Kristianssund ; (5) the sub-boreal, which occurs in the southeast of the country, especially 'round the Kristiania Fjord; and (6) the sub-Atlantic (Kristianssand coast vegeta- tion), which has its widest distribution in the coast district between Kragero and Stavanger. The arctic, boreal, and sub-boreal species of plants are warmth-loving, continental plants, while the subarctic, At- lantic, and sub- Atlantic keep chiefly to the coast districts and are insular in character. The former have immigrated dur- ing dry periods, the latter during damp periods, in the order in which they have been placed. Blytt assumed that within the period of history it is scarcely probable that any very great changes have taken place in climate or vegetation, and that the present is a dry period. Blytt ( '83) subsequently maintained that these changes of climate were due to cosmic causes, namely alterations in the eccentricity of the earth's orbit and alternate changes in the earth's position with regard to the sun, occupying periods of about 21,000 years. By the aid of this hypothesis he calculated the period from the conclusion of the Glacial Epoch down to the present time to be between 80,000 and 90,000 years. The damp and dry periods were thus of equal duration, namely 10,500 years. As Blytt moreover started with the assumption that the plants could advance only step by step in their migrations, and could not be transferred direct from Denmark or England [Vol. 2 78 ANNALS OF THE MISSOURI BOTANICAL GARDEN to Norway, he supposed that the six different flora-elements had immigrated from the south through Sweden to the places in which they are now found, but during the subsequent change of climate had died out in the intermediate regions, in which they do not grow now. Since then, Gunnar Andersson (*96, '06) has discussed this question with special reference to Sweden. He builds more particularly upon paleontological studies of the plants pre- served in peat-bogs. He assumes that the climate, after the melting of the ice, continued to grow warmer until — since Corylus Avellana, according to fossil occurrences, had a far more northerly distribution area than at the present time- it showed a mean temperature in August that was about 2.5 C. higher than at the present time. The temperature has, therefore, fallen to that of the present day. Gunnar Andersson designates the various periods after the Glacial Epoch according to the most characteristic plant, and assumes that the immigration has taken place in the follow- ing order: (1) The Dryas Flora includes certain arctic species, e.g., Dryas octopetala, Salix herbacea, S. polaris, 8. reticulata, Oxyria digyna, Arctostaphylos alpina, and others, which are supposed to have migrated into Sweden when the melting of the ice had begun, and followed this northward. The most northerly place, however, where these arctic plants are found in Sweden is in West Gothland, in about the latitude of Gothenburg. They have not been found, from this period, farther north. 2) The Betula odorata Flora is more subalpine. With it came also Salix aurita, S. caprea, and 8. cinerea, etc. (3) The Pinus sylvestris Flora immigrated during a some- what warmer period, which continued to grow warmer. In the lower, and thus older, part of the Pine Zone are found Prunus Padus, Rubus idaeus, Rhamnus Frangula, Sorbus Aucuparia, and Viburnum Opulus; in the upper, and therefore more recent, part, which has had a warmer climate, we find Alnus glutinosa, Cornus sanguined, Crataegus monogyna, 1915] WILLE — FLORA OP NORWAY 79 Corylus Avellana, Tilia europaea, Ulmus montana, etc. Here we come to the transition to the next flora. (4) Quercus Flora, which immigrated during the warmest period after the Glacial Epoch, when the mean summer temperature was about 2.5° C. higher than at the present day. In addition to Quercus pedunculata and Q. sessiliflora, there immigrated during this period Acer platanoides, Frax- inus excelsior, Hedera Helix, Viscum album, and a great num- ber of warmth-loving plants, which have since kept to the warm slates and limestones. As the last immigrants during the steady decrease of the summer temperature, Gunnar Andersson gives (5) The Fagus Flora and (6) the Picea excelsa Flora. What is new in this theory is that there is assumed to have been only one period with higher temperature since the Glacial Epoch. This, too, is supported by the results at which W. C. Brogger ('00) has arrived in his investigations of the Quaternary fossil mollusc fauna in the south of Norway. Since then, the question of the immigration of the flora into Sweden has been treated in a series of papers by R. Ser- nander ('10), who rather inclines to A. Blytt's theory, and in Norway by J. Holmboe ('03), who subscribes to that of Gunnar Andersson. The geological basis, however, upon which all investigations of the immigration of the flora into the Scandinavian penin- sula must be built, has of late years undergone considerable alteration. A number of recent discoveries of fossil plants also give new points of support. There is still, however, uncertainty concerning many points, so that the opinions of geologists and phytogeographers by no means coincide. In the first place, by counting the layers in stratified clay deposits in Sweden, Gerhard de Geer ('08) has succeeded in proving that not more than about 12,000 years have elapsed since the ice-cap of the last Glacial Period extended as far as Skaane in the south of Sweden. The ice had taken about 4,000 years to withdraw thus far from its southernmost boundary in Germany, and it afterwards took as much as about 3,000 vears to withdraw to a range of terminal moraines [Vol. 2 80 ANNALS OK THE MISSOURI BOTANICAL GARDEN in central Sweden, and in the south of Norway to the morainic ridges that extend from Fredrikshald to Moss, Horten, Arendal, etc., and are designated by the Norwegian word <» Ra. According to G. de Geer, these great terminal moraines must have been formed about 9,000 years ago when the inland ice stood still along that line for a period of about 350 years. It is a matter of indifference to us that other geologists be- lieve that this "Ra" period occurred somewhat earlier. What is of great importance in the immigration of the ilora, however, is that the extreme southeast of Norway and the center of Sweden, at the time of the "Ra" formation, lay much lower than at the present time, and sank still lower some time after the ice withdrew. It is supposed that the sea near Kristiania, during the "Ra" period, was about 660 feet higher than it now is, and a little later rose to 720 feet above its present height, which is the highest limit of the late glacial sea. But this limit differs in different parts of the country; it falls toward the coast, especially toward the west coast of Norway. At Larvik, for instance, it is about 426 feet; at Arendal, 246 feet; at Kristianssand, about 130 feet; at Mandal, 82 feet; and at Farsund, only 28 feet. Farther north it increases again, so that at Kristianssuad it is about 246 feet, and at Trondhjem, 650 feet, or almost as great as at Kristiania. THE DRYAS PERIOD I have previously ('05) endeavored to show by Dry as and Salix polaris, which A. G. Nathorst has found in a fossil state in the south of Sweden, that the arctic flora cannot have made its way thence into Norway; for during the "Ra" formation the masses of ice went right out into the sea, and when the ice had withdrawn far enough to leave open land w T ithin the "Ra" line, the climate had already altered to such an extent that the arctic flora was extinct in the south of Sweden. The earliest plants of which J. Holmboe ('03) has found remains in the southeast of Norwav, prove also to be sub- 1915] WILLE FLORA OF NORWAY 81 alpine; but farther west fossil arctic plants have been found in a number of places. D. Danielsen ('09, '12) has found, between Kristianssand and Mandal, fossil leaves of Salix polaris from 46 to 59 feet, Dryas octopetala from 46 to 52 feet, and Betula nana from 46 to 52 feet above the sea. The uppermost marine bound- ary here is from 137 to 141 feet above sea-level, but the leaves are supposed to have been carried out by currents and de- posited at a depth of perhaps 65 feet. Something similar may have taken place with most of those subsequently mentioned, as they are sometimes found covered with more or less loose material. C. F. Kolderup ( '08) has found, near Bergen, Dryas octo- petala, Salix polaris, and S. reticulata, from 115 to 130 feet above the sea, while the marine boundary lies at a height of about 190 feet above sea-level. J. Eekstad ('05, '06, '07, '08) has found Salix polaris 130 feet above the sea in Sondfjord, 187 feet above the sea in Nordfjord (marine boundary 250 feet above sea-level), and in Nordmore sometimes 82 feet, sometimes from 344 to 377 feet, above sea-level ; and Salix herbacea in Nordfjord 220 feet above the sea (marine boundary 360 feet above the sea), in Sondmore 85 feet. K. O. Bjorlykke ( '00) has found Salix reticulata near Krist- iania 540 feet above the sea, and near Trondhjem 340 feet above sea-level. P. A. Oeyen ( '04, '07) has found Dryas octopetala and Salix reticulata near Trondhjem at a height of 557 feet above sea- level, and Salix polaris in Asker, near Kristiania, 600 feet above the sea (the marine boundary at the latter locality is 692 feet above sea-level). Eemains have also been found of species that may have a subalpine occurrence, such as Betula nana, Juniperus nana, and Salix phylicif olia ; but as they are less conclusive, they are not included here. The point of especial interest is that these fossil plants on the west coast are found with remains of the high arctic mollusc Yoldia arctica, which is not now found on the shores [VOL. 82 ANNALS OK THE MISSOURI BOTANICAL GARDEiN of Norway, but on the coast of Spitzbergen, and indicates a mean temperature of from — 3 to — 7°C. and thus quite an arctic climate. At Kristianssand these arctic plant- remains are found together with remains both of Yoldia arctica and Mytilus edulis, while Salix polaris, near Kristi- ania, is found with Mytilus and far below the highest marine boundary. Two questions now present themselves, ( 1 ) did Salix polaris and other arctic vegetation continue to live during the Last Glacial Period upon a stretch of coast in the west and north of Norway that was not covered with ice, or (2) did Salix polaris and the other arctic plants immigrate from Jutland — where they lived < luring the Last Glacial Period — to the first land from which the ice disappeared at Kristianssand, and thence spread along the edge of the ice on both sides as the latter disappeared? I have previously endeavored to uphold the first of these views as the more probable, having found ('05, p. 337) that the discoveries hitherto made of the remains of arctic plants favored the belief that ' during the Last Glacial Period there lived in Norway a high-arctic vegetation upon a strip of coast that was free from ice and must have extended about as far down as the Sogne Fjord. Subsequently, as time went on, several species of high-arctic plants that had immigrated from Russia and Siberia made their way for a greater or smaller distance southward in the north of Scandinavia.' Various later discoveries of arctic plants all the way down to the south point of Norway go to prove that the iceless margin of coast may have extended thus far, at any rate par- tially. The isolated occurrence of Saxifraga A'izoon, growing upon the mountains in inner Ryfylke, east of Stavangor, is also difficult to understand unless it is assumed that it mi- grated thither from an iceless margin of coast, as this species, beyond being found in the Alps, is only known in Nordland in Norway, and in Iceland and Greenland. But it seems probable that here a number of vegetable species from the interglacial period may have survived the Last Glacial Period. This must have been the case with 1915] W1LLE FLORA OF NORWAY 83 Artemisia norvegica, whose province of distribution in Nor- way is on the Dovre and adjoining mountains in the north- west (Troldheimen), some of which could scarcely have been covered with ice during the Last Glacial Period. It is even possible to name, with considerable accuracy, some of these plants, as they form the "Greenland element' ' in the arctic flora of Norway. I designate as such those plants which Norway has in common with Iceland, Greenland, or the north of North America, but that are not found in western Siberia. These are as follows: Arnica alpina is found in the north of Norway from Salten to Alten, and also in the north of Sweden, on the Kola Penin- sula and Novaja Semlja, but not again until the east of Siberia is reached. It is also found in Greenland and on the Alps. Campanula uni flora is found in Norway from Lorn to Reisen, in Swedish Lapland and Novaja Semlja, but elsewhere only in Greenland and arctic North America. Carex nardina is found in Norway from Salten to Kvaen- angen, and in Swedish Lapland, but elsewhere only in Ice- land, Greenland, and arctic North America. Carex scirpoidea is known in Norway in Salten, and else- where only in eastern Siberia and western Greenland. Draba crassifolia is found in Norway, 'round Tromso, but otherwise only in Greenland. Pedicularis flammea is found in Norway from Salten to Lyngen, and in Swedish Lapland, but elsewhere only in Ice- land and Greenland. Plat anther a obtusata is found in Norway in Reisen and Alten, but otherwise is known only from eastern Siberia and arctic North America. A fact that possesses peculiar interest in the study of the occurrence of these and other similar species of plants in the Norwegian mountains, is the discovery in central Norway of interglacial remains of Elephas primigenius and Ovibos moschata. These great mammals became extinct at the begin- ning of the Last Glacial Period, but some of the plants that lived at the same time found a dwelling place upon the iceless [Vol. 2 84 ANNALS OF THE MISSOURI BOTANICAL GARDEN coast margin and there managed to survive that period, and then to some extent followed the retreating ice up to the mountains where thoy are now found. Andr. M. Hansen ( '04, '04 a ) even assumes that at least 300, perhaps as many as 500, kinds of vascular plants may have lived upon this supposed iceless strip of coast, which he as- sumes to have been fairly broad. These figures are perhaps rather high, but it is not j)ossible to make more exact state- ments until paleobotanical investigations have been carried out in the peat-bogs in these regions. Against the second possibility, namely, that the arctic plants may not have immigrated from Denmark to Kristians- sand until after the ice had withdrawn, several facts may be cited. These arctic plants, farther up the west coast of Norway (e.g., in Nordfjord), are found together with Yoldia arctica, and thus in a decidedly arctic climate, while those near Kristi- anssand, though, indeed, found with Yoldia, also occur with Mytilus, which indicates that the climate was somewhat milder and that the plants originated at a more recent period than those in Nordfjord. Thus the arctic plants, e.g., those in Nordfjord, cannot have immigrated thither from Kristians- sand, but may be assumed to have been there during the Last Glacial Period. On the other hand, Salix polaris near Kristiania, which ap- pears to have originated at a somewhat later period, may have been able to immigrate thither along the margin of the ice from Kristianssand ; but this cannot at present be stated with certainty, as no fossils have been found between the two points. THE BETULA ODORATA PERIOD As the ice-cap withdrew and the climate became milder, the land began to rise. In the center and south of Sweden, this took place so rapidly that a land connection was formed between Sweden and Denmark, and also between south and north Sweden, very much as it is at present. The Baltic thereby became a lake, its waters becoming gradually fresher and containing fresh-water animals, especially Ancylus fluvia- 1915] WILLE FLORA OF NORWAY 85 tills, which has given to this geological period the name of the Ancylus Period. By this upheaval of the land, a broad migration road for Fig. 4. Map of Scandinavia during the Ancylus Period: the white area represents the remainder of the great ice sheet; region indicated by parallel horizontal lines represents lake (water); region indicated by oblique cross-lines represents land. — Chiefly after De Geer. plants was opened from the southeast ^nd east to Norway. Seeds were probably carried over now and again before this upheaval of the land — as land was vacated by the [Vol. 2 86 ANNALS OF THE MISSOURI BOTANICAL GARDEN 1 ice in the southeast of Norway ; but the direct land connection facilitated the spread of all species of plants. Betula odorata was an early immigrant, and with it were a number of other plants of which fossil remains have been found, especially in peat-bogs in the southeast of Norway, namely, Betula nana, Carex ampullacea, C. filiformis, Cicuta virosa, Comarum palustre, Empetrum nigrum, Equisetum fluviatile, Ilippuris vulgaris, Juniperus communis, Meny- anthes trifoliata, Myriophyllum spicatum, Nymphaea alba, Potamogeton natans, Scirpus lacustris, Vaccinium Vitis- Idaea, Z annichellia polycarpa. But in addition to these, it may probably be assumed that the following species, which are found as subfossil remains from the subarctic or partially arctic period in Swedish peat- bogs, 2 may have migrated into Norway by this southeastern road as soon as some of the nearest land areas were free from ice. These are Andromeda polifolia, Arctostaphylos alpina, A. Uva JJrsi, Batrachium confervoides, Diapensia lapponica, Montia fontana, Myrtillus uliginosus, Oxyria digyna, Phrag- mites communis, Polygonum viviparum, Populus tremula, Potamogeton filiformis, P. praelongus, Salix aurita, 8. caprea, S. cinerea, S. phyllicif olia , S. repens, Scheuchzeria palustris, and Stachys sylvatica. During this period Hippophae rham- noides also immigrated to Sweden, but as it spread along the east coast of that country and thence through Jemtland to the north of Norway, this could not have taken place until much later, after the last of the central inland ice had melted. THE PINUS SYLVESTRIS PERIOD After Betula odorata, but during the so-called Ancylus Period in Sweden, Pinus sylvestris migrated to the south- east of Norway, while the cliimite was still comparatively cold; but, as we may gather from some of the plants that occur, especially in the latter part of the pine zone, the tem- perature became rather rapidly warmer. J. Holmboe has found in the peat-bogs of Norway the fol- ing fossil plants in the 1 By J. Holmboe ( '0.3 ) . 8 By Gunnar Anderason ('96). Alisma Plantaao, Alnus 1915] WILLE FLORA OF NORWAY 87 glutinosa, A. incana, Andromeda polifolia, Betula verrucosa, Carex Pseudocyperus, Cladium Mariscus, Corylus Avellana, Eriophorum vaginatum, Isoetes lacustris, Linnaea borealis, Lycopus europaeus, Naias marina, Nuphar luteum, Oxycoccus microcarpus, Rhamnus Frangula, Rubus Idaeus, Salix aurita, Scheuchzeria palustris, Solanum Dulcamara, Spiraea Ulmaria, and Ulmus montana. In addition to these, Gunnar Andersson has found in Swedish peat-bogs from the pine period the following species : Calla palustris, Caltha palustris, Carex riparia (?), C. vesi- caria, Ceratophyllum demersum, Cornus sanguinea, Crataegus monogyna, Eriophorum angustifolium, Galium palustre, Iris Pseudacorus, Myriophyllum alterniflorum, Naias flexilis, Myrtillus nigra, Naumburgia thyrsiflora (?), Oxalis Aceto- sella, Pedicularis palustris, Potamogeton pectinatus, Prunus Padus, Ranunculus repens, Rubus saxatilis, Rumex Hydro- lapathum, R. maritimus, Sorbus Aucuparia, Sparganium ramosum, Thalictrum flavum, Tilia cordata, Viburnum Opulus, and Viola palustris. But several of these latter species did not get as far as Norway until the succeeding warmer period, and we shall therefore find them again in the list of fossils that have been found in peat-bogs from the Oak Period. A few of them may also have immigrated by other routes, as a land connec- tion with Sweden was established not only in the south but also in the east, the ice having withdrawn to the interior of the country, and at the close of the Ancylus Period prob- ably melted away entirely. Various discoveries go to prove, for instance, that Alnus glutinosa migrated into Norway from the south, while Alnus incana came from the east. There are in Norway two quite distinct forms of Pinus sylvestris L., which by some botanists are given as species, namely, var. septentrionalis Schotte, and var. lapponica (Fr.) Hn. The second of these, which is found in abundance in Finland and the far north of Sweden, also grows in Norway, especially in the north, and on the mountains farther south, where here and there it pushes down into the valleys. It may be assumed that this P. sylvestris var. lapponica did not im- 88 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 migrate from the northeast until much later — after the ice- cap had melted in the north of Norway and Sweden, and then made its way southward. The common Pinus sylvestris, on the contrary, as we have said, undoubtedly migrated into Norway from the southeast through Sweden, which is prob- ably the way by which most of those species immigrated which are now found growing with it in the southeast of Norway. THE QUERCUS PEDUNCULATA PERIOD The climate gradually becomes warmer, the inland ice has quite disappeared, and simultaneously with its disappearance the land in a belt across central Sweden begins once more to sink (the Littorina Subsidence). When this subsidence cul- minated, the south of Sweden was a great island which, on the south, was separated — as it now is — from Denmark by Oeresund and by a broad arm of the sea, which ran from Skagerak through the district in which the lakes Venern and Vettern now lie right to the Baltic. This sea thus acquired an opening into the North Sea, and its waters gradually be- came salt. This subsidence of the land, which took place when the land around Kristiania was about 230 feet lower than it now is, did not greatly affect Norway, for it amounted in the latter to only a few yards. But it may probably be assumed that so great an arm of the sea, with a current of Gulf Stream water that even brought Gulf Stream nuts (Entada giga- lobium) with it to the shores of Bohuslaen — whence they are not carried at the present day — must have made the climate warmer and more insular than it now is. Before the sub- sidence, then, the climate must have been warm and dry, after the subsidence, warm and damp. How much warmer the climate must have been is apparent from Gunnar Andersson's investigations— following the dis- covery of fossils — on the distribution of Corylus Avellana at that time, compared with its present distribution. It appears that the mean temperature of the summer months must have been about 2.5°C. higher than it now is. In the sea off the coast of Norway there lived at that time species of the more 1915] WILLE FLORA OF NORWAY 89 Fig. 5. Map of the present and the former distribution of Corylus Avellana in Sweden. The entire area from which Corylus has disappeared is about 32,420 square miles. (For key, see upper left-hand corner of figure.) — After Gunnar Andersson. [Vol. 2 90 ANNALS OF THE MISSOURI BOTANICAL GARDEN southern mollusc genus Tapes, which shows that the average annual temperature must have been between 8 and 9°C. (Brogger, '00). Various opinions have been expressed as to whether the warmest period was before, at, or a little after, the maximum of the Littorina Subsidence in Sweden. This is of little im- portance here, but what is more important is that the earliest remains of stone implements in Norway date from this warmest period (the Tapes Period), which, therefore, in the opinion of archaeologists, must be assumed to have been about 7,000 years ago. This accords well with G. de Geer's calcu- lations from the number of clay strata. J. Holmboe has found the following species of plants, to- gether with Quercus pedunculated, in Norwegian peat-bogs: Acer platanoides, Aspidium Thelypteris, Bidens cernua, B. tripartita, Calla palustris, Car ex stellulata, C. vesicaria, Cer- atophyllum demersum, Crambe maritima, Fraxinus excelsior, Galeopsis Tetrahit, Iris Pseudacorus, Myrica Gale, Naias flexilis, Naumburgia thyrsiflora, Oxalis Acetosella, Peuce- danum palustre, Potamogeton praelongus, Ranunculus repens, Rub us fruticosus, Ruppia rostellata, R. spiralis, Scirpus ma- ritimus, Sorbus Aucuparia, Sparganium ramosum, Stachys sylvatica, Thalictrum flavum, Tilia cordata, Viola sp., Zostera marina. It will at once be seen that a good many of these species were enumerated as having been found in the south of Sweden during an earlier period, i.e., with Pinus sylvestris. This agrees very well with the assumed immigration route through Sweden, as it must have taken a considerable length of time for these plants to spread through Sweden into southern Norway. It must not, however, be forgotten that the occur- rences of plants in the peat-bogs indicate only the minimum length of time of their existence in the place in question, as they may very well have lived there for a long time before being deposited in a peat-bog, to be found there th rough the !-> of a botanist above. Gunnar Andersson has found following fossil snecies in the Oak Period in Sw 1915] WILLE — FLORA OF NORWAY 91 species being either unknown in Norway or found only in later deposits, some of them probably not having immigrated until later, together with Picea excelsa. They are Angelica sylvestris, Cakile maritima, Comus suecica (?), Helianthus peploides, Hedera Helix, Ledum palustre (f), Potamogeton crispus, Ranunculus Flammula, R. sceleratus, Sagittaria sag- ittifolia, and Viscum album. A. Blytt ('82) assumed that a great many warmth-loving species, constituting what he called the " boreal flora," must have immigrated at this time, especially several xerophilous plants, such as a number of Labiatae, Boragineae, etc. (some of which are now commonly found on the steppes of southern Russia), which still keep especially to warm slates and lime- stones in the Norwegian lowland in the east, the west, and the province of Trondhjem. Andr. M. Hansen ( '04) draws especial attention to the fol- lowing among these species, constituting what he calls the ' ' Origanum community, ' ' and which grow on open slopes with a very sunny exposure: Agrimonia Eupatoria, Androsace septentrionalis, Arenaria serpyllifolia, Calamintha Acinos, Campanula Cervicaria, Carex muricata, Centaurea Scabiosa, Dianthus deltoides, Echinospermum lappula, Origanum vul- gare, Plantago media, Polygala amara, Ranunculus Polyan- themos, Torilis Anthriscus, Trifolium medium, Turritis glabra, Verbascum nigrum, and V. Thapsus. As they grow upon dry slopes, it is not very probable that remains of them will be preserved in peat-bogs or elsewhere. Paleontologic- ally, therefore, their immigration cannot be determined, bnt something may be concluded as to their occurrence in the present day; for it appears that this warmth-loving plant community has its most connected province of distribution from the lowlands of the southeast of Norway, on the warm slates through Valdres and Gudbrandsdal, and are then met with once more on the low land of the western fjord valleys, and in the province of Trondhjem. To this last locality there is evidently also an immigration road through Jemteland from the east coast of Sweden. On the other hand, this plant community is wanting throughout so great a part of the 92 [Vol. 2 ANNALS OF THE MISSOURI BOTANICAL GARDEN Fig. 6. Sketch-map showing the distribution and journeys of the Origanum community (vertical red lines) in Scandinavia. The extent of the montane region during the warmest post-glacial period is indicated by black-dotted areas. — After Andr. M. Hansen. 1915] WILLE FLORA OP NORWAY 93 southwestern lowlands, that it can hardly be imagined that it migrated along the coast to the west and Trondhjem. It must therefore be taken for granted that these plants migrated by way of the mountain passes, some of which now lie at such an altitude that even Pinus sylvestris cannot live in the highest localities. But I have already mentioned that the summer temperature during this period was about 2.5° C. higher than it now is. We see, moreover, that remains of pine forests are found on the mountains in Norway, e.g., on the Dovre Mountains in central Norway, and on the Hard- anger plateau in the south of Norway, respectively 990 and 1,470 feet above the present highest limit of Pinus sylvestris. Under the then existing climatic conditions, the now treeless passes were clothed with forest, and warmth-loving plants were able to spread through them. A. Blytt, and after him R. Sernander, distinguishes between a boreal and a sub-boreal flora, the members of which are supposed to have been lovers of warmth and dryness, but separated in their immigration by an Atlantic flora that loved humidity and warmth. With this I cannot agree. Several of the species that Blytt ('82) classes under "sub-boreal" are found in a fossilized state together with those he calls "bor- eal"; and around Kristiania many species of these so-called different floras grow together under exactly the same condi- tions in the same localities. It seems likely, however, that the climate was more humid during the Littorina Subsidence, when the water of the Gulf Stream could make its way directly into the Baltic across central Sweden. A. Blytt ('82, p. 23) says: "Man darf des- halb mit einem hohen Grad von Wahrscheinlichkeit be- haupten, dass die atlantische Flora in dieser Regenzeit einge- wandert ist, und ihren Weg rund um den Christianiafjord gefunden hat (in derselben Weise, wie unter der folgenden Regenzeit die subatlantische)." I cannot agree in all respects with this. Those forms which Blytt calls "atlantische Arten" include a great number of species, of which some occur in what I have here called the "region of Hex Aquifolium," others constitute what I have called the "west European [Vol. 2 94 ANNALS OF THE MISSOURI BOTANICAL GARDEN coast flora,' ' while among other species belonging to Blytt's group Rhynchospora alba, Alnus glutinosa, Myrica Gale, Arnica montana, Erica Tetralix, Ranunculus Flammula, Ly- chnis Flos-cuculi, etc., may be mentioned, which grow on the low-lying land in many parts of southern Norway. As a rule, they prefer, it is true, damp places, but some species go right up to the Birch Zone on the mountains, so they may be pre- sumed to have immigrated from the southeast through Sweden; but there is nothing to prove that this took place just at the maximum of the Littorina Subsidence. As in- stances, indeed, of the contrary, Alnus glutinosa from the Birch Period and Myrica Gale from the Oak Period are found in Norwegian peat-bogs and were, therefore, much earlier. I believe that the west European coast flora on the west coast of Norway immigrated directly, by fits and starts, from England; but we will return to this later on. THE PICE A EXCELSA TERIOD According to archaeological calculations, the Scandinavian Stone Age lasted about 3,000 years, so that the Bronze Age in Scandinavia began about 4,000 years ago. During this period the climate was undoubtedly warmer than it now is, and it was not until the Bronze Age that any noticeable fall seems to have taken place. At the beginning of the Stone Age the land around Kristi- ania lay 230 feet lower than at present, but during the Stone Age it was elevated about 184 feet, and during the Bronze Age it rose to about its present height above sea-level. In the Bronze Age, or perhaps in the latter part of the Stone Age, Picea excelsa migrated into Norway from the east, from Finland through Sweden. In Finland it is si ill found as a fossil in the Oak Period, and in Sweden, especially in the north and east, it is so found, while spruce is not found fossilized in the south of Sweden or Denmark after the Glacial Epoch. In the north of Norway (Fimnark) there are occurrences of spruce that are entirely independent of the spruce's great province of distribution in the south of Norway. It appears 1915] WILLE — FLORA OF NORWAY 95 * that these northern occurrences are of a distinct form (Picea excelsa [Lam.] Link f. obovata Ledeb.), which is classed by some botanists as a separate species, and has its distribution through the north of Finland and Russia. There can, of course, be no doubt that the spruces in these northernmost occurrences immigrated independently from Finland, and probably at a later period, as there is a tradition that they were imported thither by human beings (Lapps). According to J. Holmboe, Calluna vulgaris came into Nor- way during the same recent period in which Picea excelsa made its appearance, but there is no doubt that the former immigrated from the west and then spread eastward, i.e., in the direction opposite to that in which Picea excelsa spread. Both these species have now a very wide distribution in Norway. Strange to say, there has not been found in the deposits from the Pine Period in Norwegian peat-bogs a single plant that is not to be found in the earlier periods. In Sweden the only new species found is Rubus Chamaemorus, which, how- ever, undoubtedly grew there long before, as it must on the whole be considered to be a subalpine species. This is suffi- cient to show that special conditions are necessary in order that parts of plants may be preserved in bogs, and that it will, therefore, always be only a small proportion of the plants growing around the bogs which will be so preserved. It is strange, for instance, that Taxus baccata is not found in Norwegian peat-bogs. It is found as a fossil from the Oak Period in Sweden, and must have been far more common in Norway in the early Iron Age than it is at the present time, as H. Conwents found, on examining twenty-three vessels in the Archaeological Museum in Kristiania, that eighteen of them were of Taxus and only one of Picea excelsa. According to R. Sernander ('10) the period of greatest warmth must have occurred in the Bronze Age, and he believes that it was then that Corylus Avellana was most widely dis- tributed northward. The Bronze Age, however, judging from the molluscs that were then found off the south coast of Norway, seems to have had a cooler climate than that of the [Vol. 2 96 ANNALS OK THE MISSOURI BOTANICAL GARDEN Tapes Period, i.e., the Scandinavian Paleolithic Age. On the other hand, R. Sernander believes that at the beginning of the Iron Age — about 2,400 years before our own day — so great a decline in temperature ensued that the montane plants made their way into the lowlands in many places. He inter- prets the present occurrences of alpine plants in the lowlands as relics from that period. This can, however, be the case only to a certain extent, for there is no doubt that at the present day alpine plants spread down to the lowlands and continue to grow there, provided the conditions are favorable. R. Sernander gives to his assumed cold, damp period at the beginning of the Iron Age the name employed by A. Blytt, the " sub- Atlantic period"; but the two have, in reality, very little to do with one another. A. Blytt states that his sub- Atlantic period occurred when the south coast of Norway lay from 30 to 50 feet lower than its present level, which would answer to the beerinninij: of the Bronze Ag;e. He men- 6""""0 "■"- ""^ -l^iWXX^V, x-^ tions, among other species that immigrated during the sub- Atlantic period, Carex Pseudocyperus and Cladium Mariscus, which had already immigrated in the Pine Period, and Cera- tophyllum demersum, which had immigrated in the Oak Period, besides two or three species that were certainly im- ported later in foreign grain and grass seed. I do not yet consider R. Sernander 's cold, damp "sub- Atlantic period" at the beginning of the Iron Age to have been clearly proved, although there are a few facts that speak in its favor. But even if such a cold, damp period did super- vene, its principal effect would have been to decimate the oak flora — in localities that were not especially warm — more rapidly than if the climate had gradually become colder from the Stone Age to the present time, as most people believe. Similarly, it may have promoted the occasional descent of montane plants to the lowlands, but it appears that this can also take place under the present climatic conditions, without the necessity of having recourse to relic occurrences from the "sub- Atlantic" or even from the "Dryas Period." An instance of such an occurrence is that of Dryas octo- petala at Langesund in southeastern Norway. This species 1915] WILLE — FLORA OF NORWAY . 97 is found there right down to the level of the sea, and is very common on the limestone of the locality. Together with J. Holmboe ('03), I have endeavored to prove that over the whole of the area in which Dry as appears, the latter can scarcely have existed for more than 100 years. I cannot ascribe any convincing power to the objections that have been raised against this line of argument. THE FAGUS SYLVATICA PERIOD In Norway, as already mentioned, Fagus sylvatica grows upon the southeast coast, with Larvik as a center. There is, in addition, an isolated beech-wood in Seim, to the north of Bergen, 280 miles from the nearest occurrence of beech. It was formerly believed by A. Blytt that this beech-wood in Seim was a relic of a connected distribution of beech along the coast ; but no discovery of fossils favors this idea. On the contrary, these two occurrences of beech appear to be per- fectly independent of one another. J. Holmboe ('05, '09) has endeavored to find out when the beech appeared at Larvik and in Seim. He has come to the conclusion, judging from what has been found in the peat- bogs, that at Larvik the beech immigrated considerably later than Picea excelsa. It can thus actually be assumed to have immigrated in the Iron Age, or perhaps as late as the time of the Vikings. This late immigration is in harmony with the fact that in the southeast of Norway the beech is making very rapid advance at the present time. Holmboe says that the beech-wood in Seim, from a geological point of view, is very recent, but that in any case its age should scarcely be put lower than about 1,000 years. It seems to me most probable that the beech was introduced into Norway by man in the time of the Vikings, when there was ample communication with those countries in which this so generally useful tree formed extensive forests. In Seim, near Bergen, where the beech grows, the Norwegian King Haakon the Good, who was educated in England at the court of King Athelstan, and reigned from 935 to 961, had one of his estates; and it is not unnatural to suppose that he may 98 ANNALS OK THE ,viISSOURI BOTANICAL GARDEN [Vol. 2 have tried to introduce a tree that he knew so well from his childhood and youth in England. It is certain that in the course of time man has assisted in introducing many species of plants, some consciously, as, for instance, plants for cultivation, others by chance and unconsciously. In the famous Viking ship from Osoberg, which is believed with certainty to have originated in the first half of the ninth century, fruit, seeds, and other remains of plants have been found, and have been determined by J. Holmboe ('06). The following cultivated plants were among them: Avena sativa, Corylus Avellana, Isatis tinctoria, Juglans regia, Lepidium sativum, Linum usitatissimum, Pirus Malus, and Triticum vul- gare. As Isatis tinctoria is found growing apparently wild, in certain places in Norway, there can scarcely be any doubt that it has found its way thither from localities where it had previously been cultivated as a dye-plant. This is probably also the case with Serratula tinctoria in Jaederen, near Stav- anger. The weeds found in the Oseberg ship were as follows : Capsella Bursa-pastoris, Chenopodium album, Galeopsis Tet- rahit, Lamium {purpureumf), Polygonum Convolvulus, Stell- aria media, and Urtica urens. Several of these, it is true, had immigrated earlier, as has been said of Galeopsis Tetrahit; but it shows that as early as the time of the Vikings, there were opportunities of importing foreign weeds. In monastery gardens various medicinal, household, and ornamental plants were cultivated, and one is inclined to be- lieve that several of these which now have quite a wide dis- tribution in Norway, e.g., Aquilegia vulgaris, Berberis vul- aster Sambucus nigra, etc., originally spread with the It is still easier to demonstrate a number of species of weeds that have been imported recently, and of which some appear to have a really astonishing power of spreading. J. Holmboe ( '00) has traced the spread of the following weeds from the year when they were first observed in Norway: Alyssum calycinum (1857), Anthem is tinctoria (1772?, 1807), Barbarea vulgaris (1790), Berteroa incana (1826), Bunias 1915] WILLE — FLORA OF NORWAY 99 orientalis (1812), Campanula patula (1870), Cerastium arv- ense (1817), Chrysanthemum segetum (1704), Cotula coron- opifolia (1875), Conringia orientalis (1859), Erigeron can- adensis (1874), Galinsoga parvi flora (1880), Lepidium per- foliatum (1875), L. virginicum (1889), Matricaria discoidea (1850), Rudbeckia hirta (1880), Senecio viscosus (1804-1808), Thlaspi alpestre (1874), and Xanthium spinosum (1872). Some of these plants are now among the most troublesome weeds in large and small areas in Norway. There can, I suppose, be no doubt that man, directly and indirectly, in the 7,000 years in which he has lived in Norway and maintained a lively intercourse — especially during the last 2,000 years — with the rest of Europe, must have assisted in introducing a great number of plants in addition to the above named. Among the former may be mentioned Agros- temma Githago, Anchusa arvensis, A7ithemis arvensis, Avena fatua, Brassica campestris, B. nigra, Bromus secalinus, Car- duus crispus, Centaurea cyanus, Chenopodium capitatum, C. hybridum, C. glaucum, C. polyspermum, C. rubrum, Circium arvense, Convolvidus arvensis, Euphorbia Helio- scopia, E. Peplus, Fagopyrum tataricum, Fumaria officinalis, Galeopsis angustifolia, G. Ladanum, G. speciosa, Galium Aparine, G. Mollugo, Lolium temulentum, Matricaria Cham- omilla, Raphanus Raphanistrum, Sinapis alba, S. arvensis, Sonchus asper, S. oleraceus, Spergula arvensis, Spergula vernalis, Thlaspi arvensis, etc. In addition to these there are a great many species that are generally classed in the floras under the heading "run wild" or " perhaps originally run wild, ' ' and concerning which it may certainly be assumed that they have been introduced by man's mediation in some way or other. It is no longer possible to maintain the old dogma which held that the entire plant community migrated step by step, like a regiment of soldiers, and took possession of the country under climatic conditions that were favorable to the various species, while the previous vegetation was decimated and only survived in especially favorable localities; for vegetable [Vol. 2 100 ANNALS OK THE MISSOURI BOTANICAL GARDEN species generally immigrate singly and independently of one another. It is not only man that assists in carrying plants across large sea surfaces; the wind, ocean currents, and especially birds from time to time transport seeds and other parts of plants, which, under favorable conditions, continue to grow. I will not here go further into this complex question in its entirety, but will refer to R. Sernander's ('01) detailed work on the conditions for spreading in a great number of Scandin- avian plants. I must, however, mention a few examples of probable, or certain, chance distribution. At Vaage Lake, far up the valley Gudbrandsdal, 990 feet above sea-level and separated from the innermost fjords of the west coast by 56 miles of very high mountains, grows the typical sea-shore plant, Elymus arenarius. That this occurrence represents a relic is absolutely out of the question, for the sea cannot have reached the height of Vaage Lake since the Silurian Period. But I have seen gulls flying over the lake, and they may pos- sibly have carried seeds with them, which have found a fnvor- able soil in the long sandy shores. In 1837, Goleanthus subtilis was found upon a flooded river bank a little north of Kristiania, and in 1842 a great number of specimens were collected in the same locality, probably all that existed there, for in spite of the most careful search for a number of years, the plant has never subsequently been found in that or in any other place in Norway. As its nearest habitat is in Bohemia, it can only be supposed that some wad- ing bird, in rapid flight from Bohemia to Norway, brought the seed with it; and, furthermore, that as the seed fell upon favorable soil, the plant grew up and had already begun to spread when the collection was made in 1842. I have already ('05) endeavored to show that Campanula barbata, which occurs in a limited area on the mountains of central Norway, and is not again found until we come to the mountains of Central Europe, cannot be a glacial relic, but must have been accidentally introduced into Norway (by birds'?) in recent times. 1915] WILLE FLORA OF NORWAY 101 Judging from the distribution in the present day of a num- ber of plants on the south and west coasts of Norway, it seems natural to assume that they have been brought directly over the sea from the nearest country, Denmark or England. It was thus not necessary for them to move step by step by the long route through Sweden, or even round the Kristiania Fjord, to reach their present habitats. The latter is all the less probable from the fact that certain of them seem to have been imported quite recently, when the climatic conditions cannot have been very different from those which exist at the present time. The following are instances of these : Aera setacea grows in Norway from Kristianssand to Stavanger. The species is common in Jutland in Denmark, but in Sweden is found only in the extreme south. Airopsis praecox is found from Kragero to Nordmore. It occurs, it is true, in Sweden, from the south up to Vester- gothland and Bohuslan; but from that region to Kragero is considerably farther than from Jutland, where the plant is found in abundance. Corydalis claviculata is found from Kristianssand to Haugesund. It grows wild in Denmark and England, but not in Sweden; I assume, therefore, that it immigrated from one of the former countries. Galium saxatile is found from Kristianssand to Nordmore. It grows in Sweden from Skaane to Bohuslan, but it is far more probable that it came from Jutland, where it is common. Genista tinctoria is found only at Brevik, and must have been recently imported, as there are only a few specimens of it. It is found wild only in southern Sweden, but is common in Jutland. Geranium columbinum is found in the district extending from Kragero through the west of Norway to the Trondhjem Fjord. In Sweden it has an eastern distribution from Skaane to Upland. It is common in Denmark. Heracleum australe is found from Kragero to Sondfjord. It occurs in Sweden from the south right up to Vermeland, but the distance from this district to Kragero is considerably greater than that from Jutland, where it also occurs. [Vol. 2 102 ANNALS OF THE MISSOURI BOTANICAL GARDEN Ilydrocotyle vulgaris grows here and there from Larvik to Bergen. In Sweden it does not extend farther than to Dais- land, but it is exceedingly common in Jutland. 1 Hypericum pulchrum grows in the region extending from Larvik through the west of Norway to the Trondhjem Fjord. In Sweden it is found from Hall and to Bohuslan, but it is more natural to suppose that it immigrated from Denmark or England, where it is common. Luzula sylvatica grows along the coast from Arendal to Lofoten. It is found wild only in the south of Sweden, but is common in Jutland. Rubus Radula is found from Kragero to Mandal. In Sweden it is found from Skaane to Bohuslan, but is very com- mon in Jutland. Sarothamnus scoparius grows between Grimstad and Mandal. In Sweden it is wild only in the east. It is very common in Denmark. Scirpus multicaulis grows at Arendal and in Jaederen. It is found in Sweden from Skaane to Vestergothland. It is com- mon in Denmark. Scirpus setaceus is found to the west of the Kristiania Fjord and more recently has been found also along the coast almost as far as Bergen. It is found in Sweden from Skaane to Bohuslan, but it can scarcely be supposed to have migrated thence to its most easterly occurrence in Norway, as the center of its distribution in Sweden lies farther south, and in Norway farther west. It seems, therefore, more probable that it has been brought to Norway directly from Denmark. 1 Since writing the above, I have discovered Ilydrocotyle vulgaris in a locality on Kirkeoen (Hvaler) in southeastern Norway. The locality lies about midway between the easternmost of the previously known Norwegian stations and the Swedish localities and might be looked upon as proof that the species in question had immigrated step by step through Sweden and not directly from Denmark. This, however, is not the case. On an excursion in 1907, I visited the exact spot where I later found Hydrocotyle vulgaris and I can maintain with certainty that Ilydrocotyle was not growing there at that time. The plant has, therefore, been introduced into the locality in question since that date. My opinion, therefore, that Hydrocotyle has immigrated by leaps and bounds directly from Denmark into Norway, is only strengthened by this discovery. 1915] WILLE — FLORA OP NORWAY 103 Stellaria Holostea grows along the coast from G-rimstad to Bergen. It is found in Sweden from Skaane to Bohuslan, but must have migrated into southern Norway from Denmark, where it is common. Teucrium scorodonia is found from Lyngor to Flekkef jord. In Sweden it has probably only become wild, but in Denmark it is common. Vicia cassubica is found from Kragero to Kristianssand. In Sweden it is found from Skaane to Dalsland, but it is common in Denmark. Vicia lathyroides grows along the coast from the Hvaler Islands farthest east off Norway, to Kristianssand. In Sweden, however, its distribution is easterly from Skaane to Upland, so it must be assumed that it migrated into Norway directly from Jutland in Denmark, where it is not uncommon. It will be noticed that most of these plants which I assume to have immigrated directly from Denmark (Jutland) to the south of Norway, are either bog or leguminous plants, or are such as have small seeds or stone-fruits. The carriage across water surfaces of such plants as these one would imagine could most easily take place through chance transport by birds. The distance across the Skagerak from Denmark to Norway is about 93 miles, and according to J. A. Palmen ( 76) there are regular lines followed by birds of passage from Jutland to Jaederen, as also one almost to Kristianssand and another to Risor, the very places which appear to be the center of the distribution of the majority of the above-named species which I assume to have come directly from Denmark. It is still loss probable that a number of plants that belong to the coast flora of Western Europe, and in Norway are found only in the extreme west, where the winter temperature is unusually mild (from -f-1 to +2°C), should have immi- grated from England via Denmark and Sweden, where they do not now grow, or at any rate grow only in the extreme south. If they did make such a journey, the climate must have been so much milder in the southeast of Norway that the warm period that is proved in the Stone Age would not have gone nearly far enough. A climatic change as violent 104 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 as this would have been, and that in a comparatively very recent geological period, is not probable, nor is it necessary to assume it in order to explain the occurrence of these plants in the west of Norway, if only one does not blindly adhere to the dogma that plants can migrate only step by step. As instances of plants which I assume have migrated from England direct to the west of Norway, the following may be mentioned : Asplenium Adiantum nigrum is rare from Jaederen to Kristianssund. It is found in England, but only in the very east of Denmark and the extreme south of Sweden; immi- gration from the two last-mentioned countries seems, there- fore, to be out of the question. Asplenium marinum grows in the west of Norway from Mostero to Stadt. It is found in England, but neither in Sweden nor Denmark. Erica cinerea grows on the outermost islands from Farsund to Sondmore. It is found in England, but in neither Sweden nor Denmark. Hymenophyllum peltatum grows in the outermost coast dis- tricts from Farsund to Nordf jord. It is found in England, but neither in Sweden nor Denmark. Scilla verna grows in the extreme coast regions from Sond- f jord to Sondmore. It is found in England, but neither in Sweden nor Denmark. Scolopendrium vulgare is found in two or three places between Hardanger and Sondfjord. It is common in England, but it is doubtful whether it has grown in Denmark, and in Sweden it is found only in the extreme east, in Gothland. Vicia Orobus grows farthest west, from Lister and Jaederen to Sondmore. It is common in England, but is not found in Sweden, and only here and there in Jutland. It might thus be supposed to have come from Denmark direct to Norway, but in that case it would probably grow a little farther south than it does. I consider it, therefore, most probable that it came over from England to the coast of Norway, and then spread 1915] WILLE FLORA OF NORWAY 105 along the coast southward and northward to its present limits. It also appears, according to L Hagen ('12), that the case is similar with regard to a number of mosses, a direct migra- tion from England to Norway being assumed. Hagen has so little faith, however, in the ability of these plants to migrate by leaps and bounds, that he supposes a post-glacial land con- nection with England, over which migration might gradually take place. This land bridge between Norway and England was origin- ally hypothetically constructed for the pre-glacial times by L. Stejneger ('07), who considers it necessary on zoogeo- graphical grounds. At the conclusion of his paper he says: "I think I may safely claim to have made it appear probable: "1. That if the characteristic and important portion of the animals and plants of west Norway, called the 'Atlantic' biota, in- vaded that country from Scotland, it came by way of a land bridge connecting northern Scotland with western Norway north of 59° north latitude. 2. That this land bridge existed after the first (Scandinavian) a great glaciation. "3. That part of this biota surely survived the second (Scandin- avian) glaciation along the west coast of Norway, and that possibly the climate was not too severe for all to survive. "4. That there is a possibility of a reestablishment of the land bridge during the 'Upper Forestian' stage with its congenial, more continental climate, during which the tenderer species may have immigrated, in case it should be proven that they could not have come with the hardier ones." As will appear from the foregoing pages, I have also main- tained ('05) that during the Last Glacial Period there was a stretch of coast in Norway that was free from ice, where some arctic plants, and, of course, also animals, were able to survive that period. Since then Gunnar Andersson and Selim Birger ( '12) have endeavored to give to the facts that favor this view the inter- pretation that the entire arctic flora element must have im- migrated through Sweden, and followed the receding margin of ice. I consider their arguments on this point so unconvinc- [Vol. 2 106 ANNALS OF THE MISSOURI BOTANICAL GARDEN ing, especially in view of the most recent discoveries of fossil arctic plants, and my own observations of the rock formations in the west and north of Norway, that I have come to the con- clusion that this iceless strip of coast was broader than I formerly supposed, and extended to the extreme southern point of Norway. In this respect my view is thus in perfect accordance with that of Stejneger. As to whether there was an interglacial direct land connec- tion between England and Norway, as Stejneger assumes, I cannot express an opinion, but I do not, in any case, consider it necessary for botanical reasons, although I am inclined to believe that the assumption of Stejneger will prove to b s cor- rect. On the other hand, I consider a post-glacial land con- nection between England and Norway, concerning which Stejneger himself is much in doubt, to be quite out of the question. There is nothing that can be brought forward to prove that previous to the post-glacial subsidence the land lay high enough for any real land bridge between Norway and England to exist. On the other hand, there are several facts that go to show that the southern part of the North Sea has lain higher than it now does, so that even considerable por- tions that are now under the sea were clothed with forest. This may possibly to some extent have diminished the distance between England and Norway; but the deep Norwegian Chan- nel outside the coast of Norway has certainly been in existence ever since the Last Glacial Period. But a land connection is not necessary to explain why the few species of plants that Norwav and England have in com- mon, and that must be assumed to have migrated over the North Sea, were able to come over in the course of the last 7.000 vears. It must not be forgotten that according to J. A. Palmen (76) there are two lines followed by birds of passage between England and the west of Norway ; and that there may also have been other chance means of transport. All things considered, I am inclined to believe that in trying to explain the distribution of vegetable species and the paths they have followed, we shall arrive at better results by study- in e- the wavs in which thev spread at the present time than lMfiJ WILLS — FLORA OF NORWAY 107 by setting up hypotheses of tremendous convulsions of nature such as elevated and depressed land connections, climatic changes from cosmic causes, the oscillatory movement of the poles, etc., which can neither be proved nor disproved, as they lie beyond the spheres in which our present knowledge has a firm foundation on which to stand. Literature Cited Andersson, G. ( ? 96). Svenska vaextvaerldena hiatoria. Stockholm, 1896. -, ('00). Die Entwicklungsgeschichte tier Skandinavischen Flora. Con gres Internat. Bot., Wien, 1905, Resultats seientifiques 45-97. f. ISO. 1908 , C09). Swedish climate in the late Quaternary period. Sveriges Geo logiska Undersokning. Aarbok 1909:1-88. pi 1-2. f. 1-11. 1909. , och Birger, S. ('12). Den norrlandska florana geogrnfiska foerdelning och invandringshistorie med saerskild haensyn till dess sydskandinaviska arter. Xorrlaendskt Handbibliothek v. Upsala & Stockholm, 1912. Areschoug, F. W. ('66). Bidrag till den skandinaviska vegetationens historia. Lunds Univ. Aarsskrift 1866: — '- 1800. Bjorlykke, K. O. ('00). Glaciale plantefossiler. Naturen 1900:—. 1900. Blytt, A. (76). Essay on the immigration of the Norwegian flora during alter- nating rainy and dry periods. Kristiania, 1870. , ( ? 82). Die Theorie der Kechselnden kontinentalen und insularen Kli- mate. Bot. Jahrb. 2:1-50. 18S2. , ('82). Nachtrag zu der Abhandlung: Die Theorie der wech&elnden kontinentalen und insularen Klimate. Ibid. 2:177-184. pi. i. 18S2. , ( J 83). Om vexellagring og dens mulige betydning for tidsregninges i geologien og laeren om arternea forandringer. Videnskabsselskahets For- handlinger 1883 9 : 1-31. f. 1-2. 1883. , ('00). Haandbog i Norges Flora. Udgivet ved Ove Dahl. Kristiania, 1900 BrCgger, \V. C. ('00) . Om de senglaciale og postglaciale nivaaforandringer i Kristianiafeltet ( molluskf aunan ) . Nbrges geologiske undersogelse 31 ; — . 1900-1901. •, ('05). Strandliniens beliggenhed under stenalderen. I. Det sydoestlige Norge. Norges geologiske undersogelse 41: — • Kristiania, 1905. Danielsen, D. ('09). Olacialgeologiske undersokelser omkring Kristinnssand. Nyt Mag. 47:23-95. pi. 1-J h 1909. , ('12). Kvartaergeologiske streiftog paa Soerlandet. Nyt Mag. 50: 263-382. pi. 7-9. 1912. de Geer, G. ('08), On late Quaternary time and climate. Geologiska fdreningen i Stockholm foerhandlingar. 30: — • 190S. , ('10). A thermographical record of the late Quaternary climate. Die Verltndrung dee Klima*. Stockholm, 1910. [Vol. 2, 1915] 108 ANNALS OF THE MISSOURI BOTANICAL GARDEN Hagen, I. (72) . Geografiske grupper blandt Norges loevmosser. Naturen Aarg. 36:—. 1912. Hansen, A. M. ('04). Hvorledcs bar Norge faaet sit Plantedaekke. Naturen 1904:—. 1904. , ('04a). Landnaam i Norge. En Utsigt over Bosaetningens Historic. Kristiania, 1904. , (73). Fra istiderne. Soerlandct. Videnskabaselskabets Bkrifter. I. Math.- nat. Kl. 1913":—. 1913. Holland, A. ('12). Traegraenser og Sommervtrmen. Tidsskrift for Skogbruk. Aarg. 20:—. 1012. Holmboe, J. ('00). Nogle ugraes planters indvandring i Norge. Nyt Mag. 38: 129-262. f. 1-3. 1900. , ('03). Plantereater i Norske torvmyrer. Et bidrag til den norske vegetations biatorie efter den sidste istid. Videnskahsselakabets Skrifter. I. Math.- nat. Kl. 1903 2 :— . 1903. , ('05). Studier over norske planters historic II. Nyt Mag. 43:33-60. 1905. , ('06. Ibid. III. Ibid. 44:61-74. 1806, , ('09). Boegeskogen ved Lygrefjord i Nordhordland. Bergen- Mus. Aarbog 1908 18 :— . 1901). , ('13). Kristtornen i Norge. En plantegeografisk undersoekelse. Ibid. 1913 7 :— . 1913. Kolderup, C. F. ('08). Bergensfeltet og tilstoedende trakter i senglacial oe postglacial tid. Bergeni Mus. Aarbog 1907 14 : 1-266. pi. /. f. 1-38. 1008. Nathorst, A. G. (71). Oin naagra arktiska vaextlemningar i en soettvattenslera vid Alnarp i Skaane. Lunds Univ. Ars-skrift 1870: — . 1871. Oeyen, P. A. ('04). Dryas octopetala L, og Salix reticulata i vort land foer indsjoeperioden. Videnskabsselskabets Forhandlinger 1904 1 :l-6. 1904. , ('07). Skjaelbanke-studier i Kristiania omegn. Nyt Mag. 45:27-07. f. 1-3. 1907. Palmgn, J. A. (76). Ueber die Zugstrassen der VtJgel. Leipzig, 1876. Rekstad, J. ('05). Jagttagelser fra terrasser og strandlinjer i det vestlige Norge. I. Bergens Mus. Aarbog 1905": 1-46. pi. 1. f. 1-12. 1905. , ('06). Ibid. II. Ibid. 1906 l :l-48. pi. 1. f. 1-19. 1906. -, ('07). Ibid. III. Ibid. 1907 9 :i-32. pi. 1. f. 1-15. 1907. , ('08). Bidrag til kvartaertidens historie for NordmOr. 1908. Sernander, R. ('01). Den skandinaviska vegetationens spridniiiffsbioloffi 1-459 f. 1-32. Upsala, 1901. , ('10). Die schwedischen Torfmoore als Zeugen postglazialer Klima- schwankungen. Die Veriindr. des Klimas. Stockholm, 1910. Stejneger, L. ('07). The origin of the so-called Atlantic animals and plants of Drway. Smithsonian Misc. Coll. 48:458-514. pi. 67-70. f. 1-2. western Norw 1907. Wille, N. ('05). Om Indvandringen af det arktiske Floraelement til Norm Nyt Mag. 43:315-338. 1905. , und Holmboe, J. ('03). Dryas octopetala bei Langesund. Eine gla- ciale Psoudoreliktc. Nvt Mag. 41:27-43. 1903. THE PHYLOGENETIC TAXONOMY OF FLOWERING PLANTS CHARLES E. BESSEY University of Nebraska I. Genekal Discussion Seventeen years ago in presenting a somewhat similar paper 1 to a smaller body of botanists, I began by saying that "it is as yet impossible to present a complete phylogeny of the angiosperms," and then a little later, "it will be many a year before the direct evidence we so much desire will leave no considerable gaps," and I am impelled to use the same words now as I begin this discussion to-day. For, while in this interval paleontology has uncovered many important facts whose significance is unmistakable, it is still true that there are "considerable gaps" in the record of the evolution of plants, both before and after the attainment of flower produc- tion. In other words, we are still in quest of direct testimony as to how flowers came into existence in particular, and as to the details of how and when they were modified afterwards. Yet we are not wholly without the direct testimony of the rocks in our inquiry as to the phylesis of the higher plants. And I may be permitted here to enter a defense of such a discussion as I propose to make in this paper, in reply to those who think that since much of what I shall have to say is reached by a process of deduction, or, as it is more commonly called, speculation, it can have little scientific value. And I grant that in those fields where direct observation, experiment, and induction are possible there can be no defense of the ex- clusive deductive or speculative method. There are, however, many fields of botanical inquiry in which experiment is im- possible, and observation is reduced to a minimum, and this 1 Bessey, C. E. The phylogeny and taxonomy of angiosperms. (Address of the retiring president of the Botanical Society of America, at its third annual meeting, at Toronto, Canada, August 17, 1897.) Bot. Gaz. 24: 145-178. f. 1-3. 1897. Ann. Mo. Bot. Gard., Vol. 2, 1915 (109) I VOL. 2 110 ANNALS OF THE MISSOURI BOTANICAL GARDEN a is necessarily the case when we are dealing with questions which relate to periods of time long past, as must be those involving phylogeny. Moreover, it must not be forgotten that what I propose to do is after all much like what is done in oven those sciences which we sometimes call the exact sciences. The ether of space, the undulatory theory of light, the tentative hypotheses as to the nature of electricity and gravitation, the form and extent of the universe, and the constitution of matter itself, are a few of the familiar speculations which physicists, astron- omers and chemists have made parts of the conceptions of their respective sciences. To be sure, one can go but a short distance indeed in any science without finding it necessary to erect a speculative framework upon which to arrange his ob- served facts. As Jevons has so aptly expressed it in his ' Principles of Science' (2: p. 131) : When facts are already in our possession, we frame an hypoth- esis to explain their mutual relations, and by the success or non-success of this explanation is the value of the hypothesis to be entirely judged. In the framing and deductive treatment of such hypotheses, we must avail ourselves of the whole body of scientific truth already accumulated, and when once we have obtained a probable hypothesis, we must not rest until we have verified it by comparison with new r facts. * * * Out of the infinite number of observations and experiments which are pos- sible at every moment, theory must lead us to select those few critical ones which are suitable for confirming or negativing our anticipations. A little later (p. 137) he remarks: "The true course of inductive procedure is that which lias yielded all the more lofty and successful results of science. It consists in anticipating Nature, in the sense of forming hypoth- eses as to the laws which are probably in operation; and then observing whether the combinations of phenomena arc such as would follow from the laws supposed. The investigator begins with facts and ends with them. He uses such fads as arc in the first place known to him in suggesting probable hypotheses; de- ducing other facts which would happen if a particular hypothesis is true, he proceeds to test the truth of his notion by fresh obser- vations or experiments. If any result prove different from what he expects, it leads him either to abandon, or to modify his hypothesis; but every new fact may give some new suggestion as to the laws in action." 11 1915] BESSEY — PHYLOGENETIC TAXONOMY 111 I may quote one more sentence from the Manchester logician (p. 138) : "Agreement with fact is the one sole and sufficient test of a true hypothesis. ' ' So I come with a general hypothesis of the evolution of living things, and of plants in particular. This hypothesis is based upon observed facts, which are here given such a uni- form interpretation as will make my general hypothesis, and it is this latter that I wish to discuss to-day, making such ap- plication as will enable us to arrange the flowering plants in accordance with it. I am going to confine my discussion pretty largely to the plants of the highest phylum, here restricted to those that bear flowers. Since the discovery of the pteridosperms, it is manifestly untenable to regard all seed-bearing plants as members of one phylum. In other words, the Spermatophyta of the books constitute not one phylum, but several phyla. Briefly, I shall exclude first of all the cycad phylum which began in the Paleozoic period with the pteridosperms, and has extended with many losses to the present. I shall also exclude the conifer phylum, related to but not included in the cycad phylum. These two phyla are commonly associated in a group under the name of gymnosperms, but I have no hesi- tation in keeping them as distinct phyla, the cycads lower, and the conifers higher. The remaining seed-bearing plants, whose seeds are en- closed in carpels, constituting the old group of angiosperms, I regard as a distinct phylum, and because the flower is the dominant and characteristic structure, I designate them as the Phylum Anthophyta, and they are the flowering plants about which I speak to-day. So in clearing the way for this discussion, let me show the relationship of these three phyla of higher plants by means of an analytic key, as follows : A. Gametophyte generation larger, and longer-lived than the dependent sporo- phyte generation. Here are set off the liverworts and mossea. B. Gametophyte generation smaller and shorter-lived than the independent sporophyte generation. (a) Here we set off those plants in which both generations are mostly holo- phytic and independent of one another, the megagametophyte still con- taining chlorophyll, including ferns, calamites, and lycopods. [Vol. 2 112 ANNALS OF THE MISSOURI BOTANICAL GARDEN (b) Gametophytes hysteropliytic, dependent upon, and nourished by, the sporophytes, the megagametophyte not containing chlorophyll. (1) Megagametophyte a fully developed cellular mass before the forma- tion of the eggs; microgametophytes few-celled; antherids basieidal; sperms ciliated and motile; megasporophylls open, in simple spirals to simple strobili; seeds fleshy; microsporophylls mostly multisporangiate ; bundles tracheidal, in a small, little-enlarging cylinder; pith and cortex large; steins simple; leaves ample, mostly pinnate, persistent, veins parallel cycad phylum (2) Megagametophyte a fully developed cellular mass before the forma- tion of the egg*; microgametophytes few (to one) -celled; antherid apicidal; sperms non-ciliated and not visibly motile; megasporophylls open, in well- developed strobili; seeds not fleshy; microsporophylls with few (2-8) sporangia; bundles tracheidal, in an enlarging cylinder; pith and cortex small; stems branched; leaves small, simple, persistent, veins parallel C0N1I-KJR PHYLUM (3) Megagametophyte fully developed as a cellular mass (endosperm) only after the fertilization of the egg; microgametophytes one-celled; antherids apicidal; sperms non-ciliated and not visibly motile; mega- sporophylls closed (carpels), in floral strobili (flowers), often much reduced; seeds not fleshy; microsporophylls (stamens) with four sporangia; bundles fibrovascular, in an enlarging cylinder; pith and cortex small (or bundles scattered and stem non-enlarging) ; stems branched; leaves mostly large, simple to compound, persistent to deciduous, veins netted to parallel FLOWER] NG PLANT P IIYLUM In the foregoing analysis, I have emphasized the similarities rather than the dissimilarities between the plants of these phyla, and such a statement will serve to show thai they are related, and yet no one can compare them and not be forced to the conclusion that they must have diverged from one an- other at an early period in their evolution. And this diver- gence is to be interpreted as involving the cycad phylum as the primitive group from which have sprung the conifers on the one hand and the flowering plants on the other. Following the plan which I adopted in my earlier paper, 1 I may here designate a number of generally accepted principles of classification as they apply to the flowering plants. AVhile generally accepted, these principles have rarely if ever been formulated by taxonomists or others, so that as here formu- lated they may create some surprise and perhaps some oppo- sition. For the sake of brevity I give them in the form of dicta, as rollows: A general dicta 1. Evolution is not always upward, but often it involves degradation and degeneration. 1 Lor. cit. 19151 BESSEY PHYLOGENETIC TAXONOMY 113 2. In general, homogeneous structures (with many and similar parts) are lower, and heterogeneous structures (with fewer and dissimilar parts) are higher. 3. Evolution does not necessarily involve all organs of the plant equally in any particular period, and one organ may be advancing while another is retrograding. 4. Upward development is sometimes through an increase in complexity, and sometimes by a simplification of an organ or a set of organs. 5. Evolution has generally been consistent, and when a par- ticular progression or retrogression has set in, it is per- sisted in to the end of the phylum. 6. In any phylum the holophytic (chlorophyll-green) plants precede the colorless (hysterophytic) plants, and the latter are derived from the former. 7. Plant relationships are up and down the genetic lines, and these must constitute the framework of phylogenetic taxonomy. B. DICTA HAVING SPECIAL REFERENCE TO THE GENERAL STRUCTURE OF THE FLOWERING PLANTS 8. The stem structure with collateral vascular bundles ar- ranged in a cylinder is more primitive than that with scattered bundles, and the latter are to be regarded as derived from the former. 9. Woody stems (as of trees) are more primitive than her- baceous stems, and herbs are held to have been derived from trees. 10. The simple, unbranched stem is an earlier type, from which branching stems have been derived. 11. Historically the arrangement of leaves in pairs on the stem is held to have preceded the spiral arrangement in which the leaves are solitary at the nodes. 12. Historically simple leaves preceded branched (* com pound 13. Historically leaves were first persistent ("evergreen") and later deciduous. 14. The reticulated venation of leaves is the normal structure, [Vol. 2 114 ANNALS OF THE MISSOURI BOTANICAL GARDEN and the parallel venation of some leaves is a special modification derived from it. C. DICTA HAVING REFERENCE TO THE FLOWERS OF FJX)WERING PLANTS 15. The polymerous flower structure precedes, and the oligo- merous structure follows from it, and this is accom- panied by a progressive sterilization of sporophylls. 16. Petaly is the normal perianth structure, and apetaly is the result of perianth reduction (aphanisis). 17. The apochlamydeous perianth is earlier and the gamo- chlamydeous perianth is derived from it by a symphysis of the members of perianth whorls. 18. Actinomorphy is an earlier structure than zygomorphy, and the latter results from a change from a similar to a dissimilar growth of the members of the perianth whorls. 19. Hypogyny is the more primitive structure, and from it epigyny was derived later. 20. Apocarpy is the primitive structure, and from it syncarpy was derived later. 21. Polycarpy is the earlier condition, and oligocarpy was de- rived from it later. 22. The endospermous seed is primitive and lower, while the seed without endosperm is derived and higher. 23. Consequently, the seed with a small embryo (in endo- sperm) is more primitive than the seed with a large embryo (in scanty or no endosperm). 24. In earlier (primitive) flowers there are many stamens (polystemonous) while in later flowers there are fewer stamens (oligostemonous). 25. The stamens of primitive flowers are separate (apostem- onous), while those of derived flowers are often united (synstemonous). 26. The condition of powdery poll on is more primitive than that with coherent or massed pollen. 27. Flowers with both stamens and carpels (monoclinous) pre- cede those in which these occur on separate flowers (diclinous). 1915] BESSEY PHYLOGENETIC TAXONOMY 115 — 28. In diclinous plants the monoecious condition is the earlier, and the dioecious later. Let us now endeavor to apply these principles candidly in an attempt to secure a phyletic taxonomy of the flowering plants. As a consequence, we begin with the plants that are primi- tively opposite-leaved, as shown by their first leaves ("cotyle- dons") that are always opposite. These are what we have known as dicotyledons. But this name, which was once sig- nificant, is no longer useful, and in fact has become somewhat misleading, so that I propose to substitute for it the name Oppositifoliae for the first class of the Anthophyta. Like- wise for the other class, hitherto known as the monocotyle- dons, in which the leaves are alternate from the first, and con- tinue so throughout the whole plant body, I propose the more appropriate name of Alternifoliae. In considering these two classes, it is quite evident that the first is not only the larger in the number of its species, but also that it includes many more important modifications of struc- ture than does the other. Yet there is much similarity in the kinds of modification of structure in the two classes, the larger class, from its very largeness, including many more details of modification and variation. In both classes we begin with apocarpous plants, and pro- ceed toward those that are syncarpous. So the Ranales on the one hand, and the Alismatales on the other, are near the point of beginning. In one class syncarpy is attained after the passing of a few hundred species {Alismatales, 409 species), while in the other it is not reached until much beyond the limits of the order Ranales, for it is well known that the syncarpy of many Malvales and Geraniales is distinctly in- complete, the coherence between the carpels being so feeble that they readily separate at maturity. All told, fully 10,000 species of this class are passed before complete syncarpy is attained. The strobiloid flower structure, in which the axis is elong- ated, cylindrical, spheroidal, or flattened, bearing on its sur- [Vol. 2 116 ANNALS OF THE MISSOURI BOTANICAL GARDEN face the fertile and sterile sporophylls, prevails in the earlier orders of both classes, in the smaller, continuing through the Alis mat ales, Liliales, Arales, Pahnales, and Graminales, and aggregating more than 11,700 species. In the larger class the strobiloid structure prevails throughout fourteen orders, from the Ranales to the Lamiales, and aggregating more than 53,000 species. In these strobiloid flowers, as a result of the domi- nance of the strobilar structure, we have what has been known as the hypogynous form of flower. In both classes the strobi- loid flowers show progressive modifications involving the perianth (actinomorphy to zygomorphy, diplochlamydy to achlamydy), the stamens (polystemony to oligostemony), the carpels (polycarpy to oligocarpy), the ovules (multiovulate to rariovulate). In the larger class the perianth modifications proceed with such regularity that we may recognize lower (apopetalous), and higher (sympetalous) groups of orders, but this is not observed in the smaller class, where indeed sympetaly is never more than sporadic, and does not become a fixed structure. In summary fashion I may now outline the taxonomy of the flowering plants : The opposite-leaved class (Oppositifoliae, or dicotyledons) is the first to emerge from the cycadean phylum, appearing as the ranalean complex. From this Ranalean type arises the alternate-leaved class of flowering plants (Alternifoliae, or monocotyledons) as apo- carpous Alismatales, and these soon merge into the syncarpous Liliales, which are successively more and more modified in the Arales, Pahnales and Graminales. From Liliales by a cotyloid modification the mostly actinomorphic epigynous Iridales are derived, and from these again the zygomorphic epigynous Orchidales. Eeturning to flie Ranales, we find that they give rise first to five apopetalous, polycarpellate orders with gradually in- creasing syncarpy, namely Malvales, Geraniales, Guttiferales, Rhoeadales, and Caryophyllales. From the last arise three orders of sympetalous, polycarpellate plants, the Ebenales, Ericales and Primulales, and the latter have developed the 1915] BESSEY — PHYLOGENETIC TAXONOMY 117 dicarpellate orders Gentianales, Polemoniales, Scrophulariales and Lamiales, constituting a series which shows diminishing numbers of stamens, carpels and seeds, and increasing zygomorphy. This phyletic sequence from Randies to Lami- ales constitutes the sub-class Strobiloideae, or cone-flowers. Beturning again to the Ranales, we find that they give rise to the simpler, cotyloid, apopetalous, polystemonous, poly- carpous, hypogynous Rosales (sub-class Cotyloideae), from which by the early deepening of the cotyloid structure we have the mostly polystemonous, polycarpous, epigynous Myrtales, Loasales and Cactales as a strongly developed side line. The oligostemonous Celastrales continue the main phyletic line with reducing numbers of stamens, carpels and seeds, and a gradual deepening of the cup, to the side-line of the Sapin- dales, which are eventually epigynous, and the mostly dicar- pellate Umbellales. The sympetalous, epigynous Rubiales with reduced calyx, few carpels and few seeds, pass easily into the C ampanulales , and the Asterales, the latter with but one seed in the dicarpellary, one-celled, one-seeded, inferior ovary, and with its calyx, when not obsolete, transformed into bracts, spines or bristles to form a ' ' pappus ' ' for the efficient distribu- tion of the seeds. II. Taxonomy of Flowering Plants Phylum XIV. ANTHOPHYTA. The Flowering Plants. Typically chlorophyll-green plants ( a few colorless hystero- phytes), ranging from small or even minute plants to great trees a hundred or more meters in height ; alternation of gen- erations obscured by the extreme reduction of the gameto- phyte to a condition of dependence upon the long-lived, leafy- stemmed sporophyte. Spores of two kinds (heterosporous), produced on sporophylls which are borne in modified, often much reduced strobili (flowers) ; microsporophylls (stamens) normally with four sporangia (pollen sacs) ; the microspores being set free (as " pollen") when mature; megasporophylls (carpels) folded lengthwise (constituting the " pistil") en- closing the sporangia (ovules) in which the megaspores [Vol. 2 118 ANNALS OP THE MISSOURI BOTANICAL GARDEN remain and develop the minute gametophyte ; archegones very much reduced, including little more than the egg, which is Fig. 1. Chart to show relationship of the orders. Relationship is indicated by position ; the areas are approximately proportional to the number of species in the orders. fecundated by the non-ciliated sperms (male nuclei) from tubular antherids t> format of an embryo 1915] BESSEY — PHYLOGENETIC TAXONOMY 119 sporophyte; megasporangia surrounded by one or two en- veloping indusial coats (seed coats); mature seed with or without endosperm (gametophyte tissue). The flowering plants are here held to have sprung from cycadean strobiliferous ancestors, probably of the general type of the Bennettitineae, and as a consequence those antho- phyta are considered to be primitive in which the sporophylls are many and distinct. Symphylly and syncarpy are later structural conditions than apophylly and apocarpy. So also, fewer sporophylls in the anthostrobilus is a later condition derived from the earlier polyphyllous structure. The sym- physis of sporophylls is a mode of evolution, and so is their aphanisis. The plants constituting this phylum are those commonly termed angiosperms, in contrast with the gymnosperms, in- cluding the cycads (Cycadophyta) and conifers (Strobilo- phyta). It appears to the writer, however, that these are more properly three pretty distinct phyla, and that the rela- tionship of the gymnosperms to the angiosperms is so remote that the treatment here given them is more nearly in accord- ance with what is known as to their phylogeny. There are two classes, Altemifoliae (monocotyledons) and Oppositifoliae (dicotyledons), of which the second was quite certainly the earlier, as it is now much the larger numerically. Indeed, it is becoming more probable that the monocotyledons are to be regarded as a peculiar side branch which sprang from the primitive dicotyledons after the latter had become well established. Yet the monocotyledons have not developed to as high a rank in any of their orders as have some of the dicotyledons. Although I have here changed the technical names of these two classes, there is no objection to the retention of the old terms for the English names in popular usage: accordingly on the following pages I shall frequently make such use of the old names. Class 32. ALTERNIFOLIAE (MONOCOTYLEDON- EAE). The Monocotyledons. Leaves of young sporophyte [Vol. 1 120 ANNALS OF THE MISSOURI BOTANICAL GARDEN alternate ; leaves of mature sporophyte alternate, and usually parallel- veined ; fibro-vascular bundles of the stem scattered, usually not arranged in rings. (Species about 23,700.) Sub-Class ALTERNIFOLIAE-STROBILOIDEAE. Axis of the flower from spheroidal to flattened, bearing on its sur- face the hypogynous perianth and stamens (or the stamens may be attached to the perianth), and the many or few, su- perior, separate or united carpels. Order Alismatales. Carpels separate, superior to all other parts of the flower; endosperm scanty or none (species about 409). Related to and probably derived from the Ranales of the dicotyledons. Family 1. Alismataceae. Water Plantains. Aquatic or paludose herbs with mostly radical, often large leaves; flowers small to large; perianth in two whorls of three leaves each (calyx and corolla); placenta sutural; ovules mostly solitary. Alisma, Sagittaria. (Pf. 2 1 : 227.) 1 Family 2. Butomaceae. Aquatic or paludose herbs, bear- ing narrow or broad leaves, with convergent veins; flowers large; perianth in two whorls, of three leaves each (calyx and corolla); placenta parietal; ovules many. Butomus, Lim- nocharis. (Pf. 2 1 : 232.) Family 3. Triuridaceae. Very small, pale, leafless plants growing in wet places in tropical countries. Triuris. (Pf. 2 l : 235.) Family 4. Scheuchzeriaceae. Aquatic or paludose herbs with rush-like leaves, and small flowers, with a two-whorlrd perianth, each 4— 6-parted. Triglochin, Scheuchzeria. (Pf. 2 1 :222.) Family 5. Typhaceae. Cat-tails. Aquatic or paludose herbs, with linear, sheathing leaves and cylindrical-crowded flowers; pistil 1-celled; ovule 1. Typha. (Pf. 2 1 : 183.) Family 6. Sparganiaceae. Aquatic or paludose plants with creeping rootstocks and erect stems, bearing linear 1 The abbreviation "Pf." lias reference to Engler and Prantl'a 'Naturlichen Pflanzonfamilien,' and the bold face, exponent, and Roman figures following refer respectively to "Abteilung," "Teil," and page of this publication. 1916] BESSEY PHYLOGENETIC TAXONOMY 121 leaves; flowers monoecious in dense globose heads. Spar- ganium. (Pf. 2 1 :192.) Family 7. Pandanaceae. Screw-pines. Shrubs or trees with spirally crowded, narrow, stiff leaves on the ends of the branches ; pistil 1-celled ; ovules one or many. Pandanus. (Pf . 2 1 :186.) Family 8. Aponogetonaceae. Aquatic plants with petioled, oblong, translucent leaves, with convergent veins; flowers small, spicate. Aponogeton. (Pf. 2 1 :218.) Family 9. Potamogetonaceae. River-weeds. Aquatic or paludose herbs with mostly alternate stem-leaves; flowers mostly small and inconspicuous; perianth none, or of 1-6 leaves in 1 or 2 whorls. Potamogeton, Zostera, Zannichellia. (Pf. 2i:194.) Order Liliales. Carpels united (usually 3), forming a com- pound pistil, superior; perianth (usually of 6 parts) in two similar whorls, delicate and corolla-like; endosperm copious. (Species about 3370.) Family 10. Liliaceae. The Lilies. Pistil mostly 3-celled; stamens 6 ; perianth of two similar whorls, each of three sim- ilar leaves. Lilium, Erythronium, Tulipa, Yucca, Asparagus, Allium. (Pf. 2 5 :10.) Family 11. Stemonaceae. Pistil 1-celled; stamens 4; peri- anth of two similar whorls, each of two similar leaves. Stem- ona, Croomia. (Pf. 2 5 :8.) Family 12. Pontederiaceae. Aquatic herbs with 3 or 1- celled pistil; stamens 6 or 3; perianth of two similar whorls, each of three similar or dissimilar leaves. Pontederia, Heter- anthera. (Pf. 2 4 :70.) Family 13. Cyanastraceae. Tropical African rhizomatous plants. Cyanastrum. (Syllabus, 141.) * Family 14. Philydraceae. Pistil 3-celled; stamen 1; peri- anth of two similar whorls, each of two dissimilar leaves. Philydrium. (Pf. 2 4 :75.) 1 "Syllabus" has reference to Engler and Gilg's 'Syllabus der Pflanzenfamilien,' and the numbers following refer to pages of this publication. [Vol. 2 122 ANNALS OF THE MISSOURI BOTANICAL GARDEN Family 15. Commelinaceae. Spiderworts. Succulent herbs with 3 or 2-celled pistil ; stamens 6 ; perianth of two dissimilar whorls of three similar leaves. Commelina, Tradescantia. (Pf. 2 4 :60.) Family 16. Xyridaceae. Rush-like plants with a 1-celled incompletely 3-celled pistil; stamens 3; perianth of two dissimilar whorls, each of three similar leaves. Xyris. (Pf. 2*: 18.) Family 17. Mayacaceae. Slender, creeping, moss-like plants with 1-celled pistil; stamens 3; perianth of two dissimilar whorls, each of three similar leaves. Mayaca. (Pf. 2 4 : 16.) Family 18. Juncaceae. Rushes. Herbs with narrow leaves; pistil 1-3-celled; ovules solitary or many; fruit a dry 3-valved pod. J uncus, Luzula. (Pf. 2 5 :1.) Family 19. Eriocaulonaceae. Rush-like herbs with flowers in close heads ; perianth segments 6 or less, small ; pistil 3 or 2-celled; ovules orthotropous, pendulous. Eriocaulon. (Pf. 2 4 :21.) Family 20. Thurniaceae. South American herbs, with small, 1-nerved leaves, and small axillary flowers. Thurnia. (Syllabus, 139.) Family 21. Rapateaceae. Tall, sedge-like marsh herbs with 3-celled pistil ; stamens 6, in pairs ; perianth of two dis- similar whorls, each of three similar leaves. Rapatea. (Pf. 2 4 :28.) Family 22. Naiadaceae. Slender, branching, wholly sub- merged aquatics, with sheathing, mostly opposite leaves, and monoecious or dioecious flowers. Naias. (Pf. 2 1 : 214.) Order Arales. Compound pistil, mostly tricarpellary, su- perior; ovules one or more; perianth reduced to scales or entirely wanting ; endosperm usually present. ( Species about 1052.) Family 23. Cyclanthaceae. Mostly herbaceous plants with broad, petioled leaves having parallel venation ; pistil 1-celled ; ovules many, on four parietal placentae. Cyclanthus. (Pf. 2 3 :93.) 1915] BESSEY — PHYLOGENETIC TAXONOMY 123 Family 24. Araceae. Arums. Mostly herbaceous plants with broad, petioled leaves, having reticulate venation; pistil 1-4-celled; ovules 1 or more. Anthurium, Acorus, Monstera, Symplocarpus, Calla, Philodendron, Calocasia, Caladium, A rum, A risaema. ( Pf . 2 3 : 102. ) Family 25. Lemnaceae. Duckweeds. Very small, floating, aquatic herbs ; pistil 1-celled ; ovules 1 or more. Lemna, Spiro- dela. (Pf. 2 3 :154.) Order Palmales. Compound pistil mostly tricarpellary, superior ; ovule solitary ; perianth reduced to rigid or herbace- ous scales ; endosperm copious. (Species about 1085.) Family 26. Palmaceae. Palms. Trees or shrubs with pin- nate or palmate leaves; pistil 1-3-celled; fruit a 1-seeded berry or drupe (rarely 2-3-seeded). Phoenix, Chamaerops, Calamus, Oreodoxa, Cocos. (Pf. 2 3 :1.) Order Graminales. Compound pistil reduced to 2 or 3 car- pels; ovule solitary; perianth reduced to small scales or en- tirely wanting; endosperm copious. (Species about 5795.) Family 27. Restionaceae. Rush-like herbs or undershrubs, with spiked, racemed, or panicled mostly diclinous flowers; perianth segments 6 or less, chaffy; pistil 1-3-celled; ovules orthotropous, pendulous. Restio. (Pf. 2 4 : 3.) Family 28. Centrolepidiaceae. Small rush-like herbs with mostly monoclinous flowers in spikes or heads ; perianth none ; pistil 1-several-celled ; ovules orthotropous, pendulous. Cen- trolepis. (Pf. 2 4 :11.) Family 29. Flagellariaceae. Erect or climbing herbs with long narrow leaves, and panicled flowers ; pistil 3-celled ; ovules solitary, anatropous, ascending; fruit a 1-2-seeded berry. Flagellaria. (Pf.2 4 :l.) Family 30. Cyperaceae. Sedges. Grass-like herbs with 3-ranked leaves; perianth segments bristly or none; pistil 1-celled; ovules anatropous, erect. Cyperus, Scirpus, Fim- bristylis, Rhynchospora, Car ex. (Species 1959.) (Pf. 2 2 : 98.) Family 31. Poaceae. Grasses. Mostly erect herbs with hollow, jointed stems, and 2-ranked leaves ; perianth segments [Vol. 2 124 ANNALS OF THE MISSOURI BOTANICAL GARDEN of 2-6 scales or vestiges; pistil 1-celled; ovules anatropous, ascending. Bambusa, Bromus, Triticum, Bouteloua, Avena, Agrostis, Phalaris, Oryza, Panicum, Andropogon, Zea. (Species 3545.) (Pf. 2 2 :1.) In the Poaceae the hypogynous, tricarpellary monocotyle- dons reach their culmination, as a highly specialized side line. In grasses the specialization involves plant-body, inflorescence, and flowers. Their nodose, mostly hollow, elongated stems, and long, narrow, tough leaves ; the spreading paniculate ar- rangement of their spikelets ; and their 1-celled, tricarpellary 1-ovuled pistils, producing caryopsis-fruits, are some of the more obvious indications of high specialization, suggesting the possibility that these plants, rather than the orchids, are the highest of the monocotyledons. With the Poaceae the hypo- gynous monocotyledonous phylum ends. Grasses have not given rise to other groups of plants. Sub-Class ALTERNIFOLIAE - COTYLOIDEAE. Axis of the flower normally expanded into a cup, bearing on its margin the perianth and stamens (or the latter may be at- tached to the perianth) . The carpels are thus inferior. Flow- ers from actinomorphic to zygomorphic. Order Hydrales. Flowers diclinous; compound tricarpel- lary pistil inferior to all other parts of the flower; perianth segments in each whorl alike in shape (flower regular) ; seeds without endosperm. (Species about 53.) Family 32. Vallisneriaceae. Tape-grasses. Small aquatic herbs mostly inhabiting the fresh waters of temperate cli- mates. Vallisneria, Hydrocharis, Philotria. (Pf. 2 l :238.) Order Iridales. Compound tricarpellary pistil inferior; flower-leaves in each whorl mostly alike in shape (flower reg- ular, actinomorphic) ; seeds with endosperm. (Species about 4419.) Family 33. Amaryllidaceae. Amaryllises. Leaves nar- row, or the blade broad, with longitudinal veins ; pistil 3-celled ; ovules many; stamens 6 or 3. Amaryllis, Crinum, Narcissus, Agave, Hypoxis. (Pf. 2 5 :97.) ]915] EESSEY PHYLOGENETIC TAXONOMY 125 Family 34. Haemodoraceae. Leaves sword-shaped; pistil 3-celled; ovules 1 to many; stamens 6. Haemodorum. (Pf. 2 5 :92.) Family 35. Iridaceae. Leaves sword-shaped; pistil 3- celled; ovules many; stamens 3. Crocus, Iris, Tigridia, Sisy- rinchium, Ixia, Tritonia, Gladiolus, Freesia. (Pf. 2 5 : 137.) Family 36. Velloziaceae. Woody-stemmed, leafy plants, with a 3-celled pistil containing many ovules, stamens 6 or more. Vellozia. (Pf. 2 5 : 125.) Family 37. Taccaceae. Stemless herbs, with broad pin- nately parallel- veined leaves; pistil 1-celled; ovules many; stamens 6. Tacca. (Pf. 2 5 : 127.) Family 38. Dioscoreaceae. Yams. Mostly twining herbs, with broad, petioled, longitudinally- veined leaves; pistil 3- celled; ovules 2 in each cell; stamens 6. Dioscorea, Testudin- aria. (Pf. 2 5 :130.) Family 39. Bromeliaceae. Pineapples. Leaves mostly rosulate; external perianth whorl calycine; pistil 3-celled; ovules many; stamens 6. Tillandsia, Dendropogon, Ananas. (Pf. 2 4 :32.) Family 40. Musaceae. Bananas. Large herbs, the stem often composed of the sheathing leaf -bases ; perianth petaloid of 6, often dissimilar segments; stamens 6; pistil 3-celled; ovules 1 to very many. Strelitzia, Musa. (Pf. 2 6 : 1.) Family 41. Zingiberaceae. Gingers. Perennial, medium- sized herbs, with creeping or tuberous rootstocks; perianth irregular; stamen 1, anther 2-celled, with several "stamin- odes ' ' ; pistil 3-celled ; ovules 1 or more in each cell. Curcuma, Zingiber, Amomum. (Pf. 2 6 : 10.) Family 42. Cannaceae. Cannas. Perennial herbs of medium size, with simple pinnately-veined leaves; perianth irregular; stamen 1, anther 1-celled, with several "stamin- odes ' ' ; pistil 3-celled ; ovules 1 to many. Canna. (Pf . 2 6 : 30. ) Family 43. Marantaceae. Perennial herbs of variable habit : leaves parallel or pinnately veined ; perianth irregular ; functional stamen 1, with several ' * staminodes ' ' ; pistil 3 [Vol. 2 126 ANNALS OF THE MISSOURI BOTANICAL GARDEN celled; ovules 1 in each cell. Calathea, Maranta. (Pf. 2° : 33.) Order Orchidales. Compound tricarpellary pistil inferior ; flower-leaves in each whorl mostly unlike in shape (Jlower irregular, zygomorphic) ; seeds numerous, minute, without endosperm. (Species about 7578.) Family 44. Burmanniaceae. Flowers irregular; stamens 3 or 6. Burmannia. (Pf. 2 6 :44.) Family 45. Orchidaceae. Orchids. Flowers irregular; stamens 1 or 2. Cypripedium, Orchis, Platanthera, Vanilla, Spiranthes, Epidendrum, Dendrobium, Oncidium. (Species 7521.) (Pf.2«:52.) In the Orchidales, and especially in the Orchidaceae, we have what is generally regarded as the highest development of monocotyledonous plants, and yet it must be acknowledged that many of their most striking flower structures are rather easily made entomophilous modifications of the perianth, the most mobile portion of the plant. In many ways the ' ' grassy" plants (especially the Poaceae) show greater and more pro- found structural modifications than do the much more con- spicuous orchids. With the orchids the epigynous monocoty- ledonous phylum ends. Class 33. OPPOSITIFOLIAE (DICOTYLEDONEAE). The Dicotyledons. Leaves of young sporophyte opposite; leaves of mature sporophyte opposite or alternate, usually reticulate-veined; fibrovascular bundles of the stem in one or more cylindrical layers. (Species about 108,800.) As indicated above the dicotyledons are here considered to have had their beginning earlier than the monocotyledons, which must be regarded as having diverged very early from the primitive dicotyledons, and developed into a relatively small lateral branch. The point of divergence of the mono- cotyledons from the dicotyledons must have been in the order Ranales, probably in the neighborhood of the Ranunculaceae . It is not probable that the early (woody) magnoliads or ano- nads gave rise to the monocotyledonous divergence ; it is much more probable that this modification arose after the reduction had taken place from the ligneous to the herbaceous Ranales. 1915] BESSEY PHYLOGENETIC TAXONOMY 127 Here we have a possible explanation of the marked herbaceous- ness of monocotyledons as contrasted with the general ten- dency toward a more ligneous structure in dicotyledons. Sub - Class OPPOSITIFOLIAE - STROBILOIDEAE. ' 'Cone flowers." Axis of the flower normally cylindrical, spherical, hemispherical or flattened, bearing on its surface the hypogynous perianth, stamens and pistils (or the stamens may be attached to the corolla). Super - Order Strobiloideae-Apopetalae-Polycaepellatae. Carpels typically many, separate or united; petals separate. Flowers mostly actinomorphic. This super-order has much in common with the Alismatales, and also with the Cotyloideae- Apopetalae. In fact, these three groups appear to have diverged from a common point of origin. Order Eanales. All parts of the flower mostly spirally arranged (acyclic), free (not united) ; carpels typically many, separate (or rarely united), rarely reduced to 1; stamens gen- erally indefinite ; embryo mostly small, in copious endosperm. (Species about 5551.) The twenty-four families here included in the order Randies naturally group themselves about three centers, the magnolias (Magnoliaceae), the anonas (Anonaceae), and the buttercups (Ranunculaceae) . The plants in these centers are typically diplochlamydeous, polycarpellate, hermaphrodite, and actino- morphic, and the modifications in the surrounding families have been such as to result in an achlamydeous structure, which may be monocarpellate, diclinous, and even zygomorphic. Ranalean evolution has thus been one of more and more marked simplification of flower structure. It is interesting to observe that while the families of Ranales have thus been evolved, the order has given rise to no less than five phyletic groups of full ordinal rank. One of these (Malvales) has produced a further modification (Sarraceni- ales), for three of them the evolutionary development came to a stand-still with the ordinal limits (Geraniales, Guttiferales and Rhoedales), while the virile Caryophyllales continued a development beyond its ordinal limits into the Ebenales, Eri- [Vol. 2 128 ANNALS OF THE MISSOURI BOTANICAL GARDEN cales and Primulales, and through the latter into Gentianales, Polemoniales and Scrophulariales to the end of this phyletic line in the Lamiales. Family 46. Magnoliaceae. Magnolias. Petals present, usually many ; receptacle usually elongated ; shrubs and trees with alternate leaves and usually large flowers. Magnolia, Liriodendron. (Pf. 3 2 : 12.) Family 47. Calycanthaceae. Petals present, usually many; seeds without endosperm ; shrubs with opposite leaves. Caly- canthus. (Pf.3 2 :92.) Family 48. Monimiaceae. Petals absent; carpels many, 1-ovuled, embedded in the receptacle; trees and shrubs with opposite or whorled leaves, and diclinous flowers. Kibara, Monimia, Siparuna. (Pf. 3 2 : 94.) Family 49. Cercidiphyllaceae. Trees with naked dioe- cious flowers, many stamens, and a single whorl of 2-5 free carpels. Cercidiphyllum. (Pf. 3 2 :21.) Family 50. Trochodendraceae. Trees and shrubs with naked flowers, many stamens, and a single whorl of 5 to many partly connate carpels. Trochodendron. (Pf. 3 2 :21.) Family 51. Leitneriaceae. Shrubs with alternate leaves and dioecious flowers in catkins ; perianth minute or ; pistil 1-celled, 1-ovuled ; endosperm minute. Leitneria. (Pf . 3 1 : 28. ) Family 52. Anonaceae. Papaws. Petals present, in two whorls of 3 each; stamens and carpels many; endosperm ruminated; trees or shrubs with alternate leaves. Asimina, Anona. (Pf. 3 2 :23.) Family 53. Lactoridaceae. Much-branched shrubs of the South Pacific Islands, with alternate leaves, and apetalous flowers. Lactoris. (Pf. 3 2 :19.) Family 54. Gomortegaceae. Large trees of South America, with opposite evergreen leaves, and acyclic flowers; carpels 2-3, each with 1 ovule. Gomortega. (Pf. Nachtrage zu Teil n-iv, 172.) Family 55. Myristicaceae. Nutmegs. Sepals 3; petals absent; pistil 1 (or a second rudiment), 1-seeded; endosperm 1915] BESSEY PHYLOGENETIC TAXONOMY 129 ruminated; trees or shrubs with alternate leaves and small, inconspicuous, dioecious flowers. Myristica. (Pf. 3 2 :40.) Family 56. Saururaceae. Rhizomatous marsh herbs, with alternate leaves; flowers perfect, small, spicate; perianth 0; carpels 3-4, more or less united. Saururus. (Pf. 3 1 : 1.) Family 57. Piperaceae. Peppers. Herbs, shrubs, and trees with alternate (or opposite) leaves; flowers perfect or diclinous, mostly spicate ; perianth ; pistil 1-celled, 1-ovuled ; endosperm present. Piper, Macropiper. (Pf. 3 1 : 3.) Family 58. Lacistemaceae. Tropical American shrubs and trees with alternate leaves, and perfect flowers; perianth mostly ; stamen 1 ; pistil 3 or 2-carpellary. Lacistema. (Pf. S*:14.) Family 59. Chloranthaceae. No perianth whatever; pistil 1, with 1 ovule ; mostly tropical trees and shrubs, with opposite leaves, and small flowers. Chloranthus. (Pf. 3 1 : 12.) Family 60. Ranunculaceae. Buttercups. Petals present in one whorl, or absent ; sepals mostly deciduous ; stamens and carpels indefinite, the latter usually separate; mostly herbs with alternate leaves. Myosurus, Ranunculus, Anemone, Cle- matis. (Pf. 3 2 :43.) Family 61. Lardizabalaceae. Petals and sepals 6 each; 6; twining or erect shrubs, with alternate leaves. Akebia, Lardizabala. (Pf. 3 2 :67.) Family 62. Berberidaceae. Barberries. Petals usually present, in 1-3 whorls; stamens few; carpel 1 (rarely more), with many ovules; mostly shrubs with alternate leaves and perfect flowers. Podophyllum, Berberis. (Pf. 3 2 :70.) Family 63. Menispermaceae. Moonseeds. Petals present, in 2 whorls ; carpels 3 or more ; twining shrubs with alternate leaves and small dioecious flowers. Menispermum, Cocculus. (Pf. 3 2 :78.) Family 64. Lauraceae. Laurels. Aromatic trees and shrubs with alternate simple leaves and small flowers ; petals ; carpel 1 ; ovule 1, pendulous ; endosperm 0. Cinnamomum, Persea, Ocotea, Umbellularia, Sassafras, Litsea, Laurus. (Pf. 3 2 :106.) amens [VOL. 2 130 ANNALS OF THE MISSOURI BOTANICAL GARDEN Family 65. Nelumbaceae. Lotuses. Large aquatic herbs with peltate leaves, large acyclic flowers, with many stamens, and many separate carpels, the latter immersed in the flattish axis ("receptacle"); seeds 1 or 2, endosperm 0. Nelumbo. (Pf. 3 2 :1.) Family 66. Cabombaceae. Water-shields. Small aquatic herbs with floating, sometimes peltate leaves, and few to many stamens, and separate carpels (not immersed) ; seeds 2 or 3; endosperm present. Cabomba, Brasenia. (Pf. 3 2 :2.) Family 67. Ceratophyllaceae. Aquatic herbs with verti- cillate, divided leaves ; flowers diclinous ; perianth ; stamens 12-16; carpel 1, 1-ovuled; endosperm scanty. C e r at o phyllum . (Pf. 3 2 :10.) Family 68. Dilleniaceae. Petals present, in one whorl; sepals persistent; stamens numerous, indefinite; carpels from many to 1, with 1 or more seeds ; endosperm copious ; mostly shrubs and trees with alternate leaves, and perfect flowers. Dillenia, Actinidia. (Pf. 3 6 : 100.) Family 69. Winteranaceae. Aromatic trees with alternate leaves; flowers perfect; sepals 4-5; petals 4-5 (or 0) ; stamens 20-30 ; pistil 2-5-carpellary, with as many parietal placentae ; endosperm copious. Winter ana, Cinnamodendron. (Pf. 3 6 : 314.) Order Malvales. Pistil usually of 3 to many weakly united carpels, with as many cells (sometimes greatly reduced) ; ovules mostly few; stamens indefinite,monadelphous, branched, or by reduction separate and few; endosperm present or ab- sent. (Species about 3829.) Family 70. Sterculiaceae. Trees and shrubs with alternate leaves; flowers perfect or diclinous, with or without petals; stamens monadelphous or polyadelphous, 2-celled; pistil 4-many-celled ; endosperm present or 0. Theobroma, Ster- culia. (Pf. 3 6 : 69.) Family 71. Malvaceae. Mallows. Herbs, shrubs, and trees with alternate leaves; flowers perfect, with petals; stamens monadelphous, 1-celled ; pistil 5-many-celled ; endosperm little 1915] BESSEY PHYLOGENETIC TAXONOMY 131 or 0. Abutilon, Althaea, Malva, Hibiscus, Gossypium. (Pf. 3 G :30.) Family 72. Bombacaceae. Tropical trees with alternate, palmate leaves; sepals and petals present; staminal column 5-8-cleft. Adansonia, Bombax. (Pf. 3 6 : 53.) Family 73. Scytopetalaceae. Trees of the southern hemi- sphere, with alternate leathery leaves; sepals small; petals much larger, valvate; stamens many. S cyt o p et alum . (Pf. Nachtrage zu Teil ii-iv, 242.) Family 74. Chlaenaceae. Madagascar trees and shrubs with alternate leaves; inflorescence dichotomous; petals con- torted. Rhodochlaena, Leptochlaena. (Pf. 3 6 :168.) Family 75. Gonystylaceae. East Indian trees with leath- ery, evergreen leaves, pentamerous flowers, and a berry-like fruit. Gony stylus. (Pf. Nachtrage zu Teil ii-iv, 231.) Family 76. Tiliaceae. Lindens. Trees, shrubs (and herbs) with mostly alternate leaves; flowers mostly perfect, with petals; stamens free, 2-celled; pistil 2-10-celled; endosperm present or 0. Corchorus, Tilia, Grewia. (Pf. 3 6 :8.) Family 77. Elaeocarpaceae. Tropical trees and shrubs, with alternate or opposite simple leaves; sepals and petals present; stamens distinct, many; pistil of 2-several carpels. Elaeocarpus, Aristotelia. (Pf. 3 6 : 1.) Family 78. Balanopsidaceae. Australian trees and shrubs with alternate leaves; flowers dioecious, apetalous, the stam- inate in catkins, the pistillate solitary, producing acorn-like, 2-celled, 2-seeded fruits; seeds endospermous. This family is doubtfully given place here, and it may be that it should be placed near the Fagaceae, as is done by Baillon. Balanops. (Pf. Nachtrage zu Teil ii-iv, 114.) Family 79. Ulmaceae. Elms. Trees and shrubs with al- ternate, simple leaves, small apetalous flowers, a 1-celled (rarely 2-celled) ovary, which develops into a samara, drupe or nut. Ulmus, Celtis, Zelkova, Planera. (Pf. 3 1 : 59.) Family 80. Moraceae. Figs. Trees, shrubs, and herbs, mostly with a milky juice, and alternate or opposite leaves; [Vol. 2 132 ANNALS OF THE MISSOURI BOTANICAL GARDEN flowers apetalous, diclinous (monoecious or dioecious) ; ovary 1-celled, 1-ovuled. Morus, Toxylon (Madura), Broussonetia, Dorstenia, Artocarpus, Castilloa, Antiaris, Ficus, Humulus, Cannabis. (Pf. 3 1 : 66.) Family 81. Urticaceae. Nettles. Herbs, shrubs, and trees with alternate or opposite leaves; flowers mostly diclinous, apetalous; stamens few, 2-celled; pistil monocarpellary, 1- celled, mostly 1-seeded; endosperm none. Urtica, Boehmeria. Order Sarraceniales. Pistil of 3-5 carpels united; centae parietal or central ; seeds small, numerous, endosperm- ous; herbs with "insectivorous" leaves; related to tho mal- lows, with which they should possibly be included. (Species about 66.) Family 82. Sarraceniaceae. Pitcher-plants. Herbs with pitcher-shaped leaves, and perfect flowers ; sepals 4-5 ; petals 5, rarely 0; stamens indefinite; pistil 3-5-carpellary. Sarra- cenia, Darlingtonia. (Pf. 3 2 : 244.) Family 83. Nepenthaceae. Pitcher-plants. Tropical un- dershrubs with pitcher-shaped leaves and dioecious flowers; sepals 4 or 3; petals 0; stamens 4-16; pistil 4-3-carpellary. Nepenthes. (Pf. 3 2 :253.) Order Geraniales. Pistil of several (5-2) mostly weakly united carpels; ovules 1-2 (or many), mostly pendulous, at- tached at the inner angle of the carpel. (Species about !>268.) Family 84. Geraniaceae. Geraniums. Herbs, shrubs, and trees, with opposite or alternate (compound or simple) leaves; torus elongated ; stamens 10 ; pistil mostly 5-celled ; ovules few ; endosperm sparse or 0. Geranium, Pelargonium, Erodium. (Pf. 3 4 :1.) Family 85. Oxalidaceae. Sorrels. Herbs, rarely shrubs or trees, the juice sour ; leaves mostly 3 or more foliate ; flowers pentamerous, regular; stamens 10; ovules many; endosperm fleshy. Oxalis. (Pf. 3 4 :15.) Family 86. Tropaeolaceae. Nasturtiums. Succulenl, prostrate or climbing herbs, with alternate, peltate leaves, and 1915] BESSEY — PHYLOGENETIC TAXONOMY 133 irregular, long-peduncled, spurred flowers; stamens 8; ovary tricarpellary ; ovules solitary; endosperm 0. Tropaeolum. (Pf. 3 4 :23.) Family 87. Balsaminaceae. Touch-me-nots. Succulent herbs, mostly erect, with opposite or alternate leaves, and ir- regular, spurred axillary flowers; stamens 5; ovary penta- carpellary, ovules many; endosperm 0. Impatiens. (Pf. 3 5 :383.) Family 88. Limnanthaceae. Succulent marsh herbs, with alternate, pinnate leaves; flowers pentamerous; stamens 10; carpels 5; endosperm 0. Limnanthes. (Pf. 3 5 : 136.) Family 89. Linaceae. Flaxes. Herbs and shrubs, with al- ternate simple leaves; pistil 3-5-celled; endosperm fleshy (or rarely 0). Linum. (Pf. 3 4 : 27.) Family 90. Humiriaceae. Trees with alternate simple leaves; pistil 5-7-celled; endosperm copious. Humiria, Sac- co glottis. (Pf. 3 4 :35.) Family 91. Erythroxylaceae. Shrubs and trees, with mostly alternate, simple leaves ; flowers pentamerous ; stamens 10; ovary 3-4-carpellary ; fruit a drupe; endosperm fleshy. Erythroxylon. (Pf. 3 4 : 37.) Family 92. Zygophyllaceae. Herbs and shrubs with usually opposite, compound leaves; pistil lobed, 4-5-celled; endosperm copious (or rarely 0). Z y g o phyllum , Guaiacum, Larrea. (Pf. 3 4 :74.) Family 93. Cneoraceae. Shrubs with alternate entire leaves, trimerous or tetramerous flowers ; pistil 3 or 4-celled, each cell with one ovule; endosperm fleshy. Cneorum. (Pf. 3 4 :93.) Family 94. Rutaceae. Oranges. Herbs, shrubs, and trees with glandular-dotted, opposite, simple, or compound leaves ; pistil lobed, 4^5-celled ; endosperm fleshy or 0. Xanthoxylum, Ruta, Dictamnus, Ptelea, Limonia, Citrus. (Pf. 3 4 : 95.) Family 95. Simarubaceae. Trees and shrubs with gener- ally alternate, non-glandular, simple, or compound leaves; pistil lobed, 1-5-celled; endosperm fleshy or 0. Simaruba, Quassia, Holacantha, Ailanthus. (Pf. 3 4 : 202.) [Vol. 2 134 ANNALS OF THE MISSOURI BOTANICAL GARDEN ■J Family 96. Burseraceae. Balsamic trees and shrubs with alternate compound leaves; pistil 2-5-celled; endosperm 0. Protium, Canarium, Bur sera. (Pf. 3 4 : 231.) Family 97. Meliaceae. Trees and shrubs with alternate compound leaves; pistil 3-5-celled; endosperm present or 0. Swietenia, Melia. (Pf. 3 4 : 258.) Family 98. Malpighiaceae. Trees and shrubs with usually opposite, simple or lobed leaves; pistil tricarpellary ; endo- sperm 0. Stigmatophyllon, Malpighia, Byrsonima. (Pf. 3 41.) Family 99. Trigoniaceae. Climbing shrubs with opposite simple leaves and irregular flowers; pistil tricarpellary; seeds many, endospermous. Trigonia. (Pf. 3 4 :309.) Family 100. Vochysiaceae. Shrubs and trees with oppo- site or whorled leaves; sepals 5; petals 1, 3, or 5; stamens several, usually but one fertile; pistil tricarpellary; seeds few; endosperm 0. Vochysia, Qualea. (Pf. 3 4 : 312.) Family 101. Polygalaceae. Herbs, shrubs, and trees with alternate leaves; flowers irregular; sepals 5; petals 3-5; stamens usually 8; ovary 2-celled; ovules solitary; endosperm present or 0. Poly gala, Xanthophyllum. (Pf. 3 4 :323.) Family 102. Tremandraceae. Small shrubs with alternate, opposite, or whorled leaves ; flowers regular ; sepals and petals 3, 4, or 5 each; stamens twice as many; ovary 2-celled; ovules mostly solitary; endosperm fleshy. Tremandra, Tetratheca. (Pf.3 4 :320.) Family 103. Dichapetalaceae. Trees and shrubs with alter- nate simple leaves; pistil 2-3-celled; endosperm 0. Dicha- petalum, Tapura. (Pf. 3 4 :345.) Family 104. Euphorbiaceae. Spurges. Herbs, shrubs, and trees, mostly with a milky juice and alternate or opposite leaves ; flowers diclinous, with a perianth of 1 or 2 whorls, or wanting; stamens 2-celled, free or united; pistil usually 3- celled; ovules mostly solitary; endosperm copious. Euphorbia, Pedilanthus, Phyllanthus, Croton,Mallotus,Acalypha,Ricinus, Jatropha, Manihot, Stillingia. (Species 4319.) (Pf. 3 5 : 1.) 1915] BESSEY — PHYLOGENETIC TAXONOMY 135 Family 105. Callitrichaceae. Floating herbs with opposite sessile leaves ; flowers diclinous, sessile in the leaf-axils ; peri- anth none ; stamens 1 or 2 ; ovary 2-celled ; endosperm fleshy. Callitriche. (Pf. 3 5 :120.) Order Guttiferales. Pistil mostly of 2 or more carpels, 2-several-celled, with axile placentae; stamens usually in- definite; endosperm usually wanting. (Species. about 3138.) Family 106. Theaceae. Teas. Trees and shrubs usually with alternate leaves ; inflorescence various ; petals imbricated ; seeds few; endosperm scanty or 0. Thea, Stuartia. (Pf. 3 6 : 175.) Family 107. Cistaceae. Herbs and shrubs with opposite (or alternate) leaves; sepals 3-5; petals 5; stamens many; pistil 3-5-carpellary, with as many parietal placentae; seeds usually many, endospermous. Cistus, Helianthemum, Hud- sonia. (Pf. 3 8 :299.) Family 108. Guttiferaceae. Trees, shrubs, and rarely herbs, with opposite or whorled, glandular-dotted leaves; in- florescence often trichotomous, with flowers mostly diclinous ; petals 2-6, or more, imbricated or contorted; stamens many; carpels mostly 3-5; endosperm 0. Hypericum, Mammea, Clusia, Garcinia. (Pf. 3° : 194.) Family 109. Eucryphiaceae. Evergreen trees of the south- ern hemisphere, with opposite leaves ; flowers large, tetramer- ous; stamens many; pistil many-celled; seeds endospermous. Eucryphia. (Pf. 3 6 :129.) Family 110. Ochnaceae. Tropical shrubs and trees with alternate, coriaceous, simple leaves; pistil lobed, 1-10-celled; endosperm fleshy or 0. Ochna. (Pf. 3°: 131.) Family 111. Dipterocarpaceae. Tropical, resiniferous trees and shrubs with alternate leaves ; inflorescence panicled ; flow- ers regular, perfect ; petals contorted ; fruiting calyx enlarged, and wing-like; carpels few (3-1) ; seeds 2 in each cell; endo- sperm 0. Dipt ero car pus. (Pf. 3 6 :243.) Family 112. Caryocaraceae. Tropical trees and shrubs, with alternate trifoliate leaves, large showy flowers, and many :vol. 2 136 ANNALS OF THE MISSOURI BOTANICAL GARDEN long stamens; seeds solitary; endosperm scanty or 0. Cary- ocar. (Pf. 3 G :153.) Family 113. Quiinaceae. South American trees and shrubs, with opposite or whorled simple leaves; sepals 4-5; petals 4-5 ; stamens 15-30. Quiina. (Pf. 3° : 165.) Family 114. Marcgraviaceae. Tropical trees and shrubs, with alternate, simple leaves; sepals 2-6; petals as many; stamens as many or more ; ovary 3-5-celled ; seeds many ; en- dosperm 0. Marcgravia. (Pf. 3 fl : 157.) Family 115. Flacourtiaceae. Mostly tropical trees and shrubs with alternate leaves ; sepals 2-15 ; petals 10-0 ; stamens indefinite; carpels 2-10; seeds endospermous. Pangium, Fla- cou rtia, S amy da. ( Pf . 3 6a : 1. ) Family 116. Bixaceae. Tropical shrubs with alternate leaves ; sepals 3-7 ; petals large ; stamens indefinite ; pistil bi- carpellary; seeds endospermous. Bixa. (Pf. 3 6 :307.) Family 117. Cochlospermaceae. Tropical trees and shrubs with alternate lobed or compound leaves; petals large; sta- mens indefinite; pistil 3-5-carpellary ; endosperm copious. Cochlospermum. (Pf. 3 6 : 312, and Nachtrage zu Teil ii-iv, 251.) Family 118. Violaceae. Violets. Herbs and shrubs with alternate (or opposite) leaves; sepals and petals 5, irregular; stamens 5; pistil 3-carpellary with 3 parietal placentae; en- dosperm copious. Rinorea, Ilybanfhus, Viola. (Pf. 3°: 322.) Family 119. Malesherbiaceae. South American branching herbs or undershrubs, with perfect, regular, pentamerous flowers; endosperm fleshy. Malesherbia. (Pf. 3 Ga :65.) Family 120. Turneraceae. Tropical herbs and shrubs with alternate leaves; flowers perfect; sepals and petals dis- similar; stamens definite; ovary tricarpellary; endosperm copious. Turnera. (Pf. 3 6 ' 1 : 57.) Family 121. Passifloraceae. Passion flowers. Climbing herbs and shrubs (a few trees) with alternate leaves; flowers perfect, regular; sepals and petals similar, distinct; stamens definite; ovary free; endosperm fleshy. Adenia, Passijlora. (Pf. 3 Ca :69.) 1915] BESSEY — rHYLOGENETIC TAXONOMY 137 Family 122. Achariaceae. South African herbs and under- shrubs, related to the Passifloraceae; but with the petals united. Acharia. (Pf. 3« a :92.) Family 123. Caricaceae. Papaws. Succulent-stemmed tropical trees, mostly with palmate leaves and milky juice; flowers pentamerous ; fruit a many seeded berry ; endosperm fleshy. Carica. (Pf. 3 6a :94.) Family 124. Stachyuraceae. Asiatic shrubs and trees with alternate leaves; sepals 4; petals 4; stamens 8; endosperm fleshy. Stachyurus. (Pf. 3 6 :192.) Family 125. Koeberliniaceae. Leafless, thorny Texan and Mexican shrubs, with tetramerous flowers; pistil bicarpellary ; seeds many; endosperm scanty. Koeberlinia. (Pf. 3 6 :319.) Order Bhoeadales. Pistil of 2 or more united carpels, mostly 1-celled, with parietal placentae ; stamens indefinite or definite ; endosperm none or copious. (Species about 2856.) Family 126. Papaveraceae. Poppies. Mostly milky-juiced plants, with alternate leaves, and regular or irregular flowers ; sepals 2-3; petals 4 or more (or 0) ; stamens indefinite; pistil many-carpellary ; seeds usually many; endosperm fleshy. Eschscholtzia, Sanguinaria, Argemone, Papaver, Bicuculla, Fumaria. (Pf.3 2 :130.) Family 127. Tovariaceae. Annual herbs of the tropics, with alternate leaves ; 8-merous flowers, and many seeds, with scanty endosperm. Tovaria. (Pf. 3 2 :207.) Family 128. Nymphaeaceae. Water-lilies. Aquatic herbs with floating leaves, and regular flowers; petals present, in 1-many whorls (really acyclic); pistils closely united; seeds many, endospermous. Victoria, Castalia, Nymphaea. (Pf. 3~:1.) Family 129. Moringaceae. Trees of the tropics, with de- compound leaves and pentamerous, zygomorphic flowers, and producing bean-like tricarpellary pods; endosperm 0. Mor- inga. (Pf. 3 2 :242.) Family 130. Resedaceae. Mignonettes. Herbs and shrubs with scattered leaves and zygomorphic flowers; sepals 4-8 Vol. 2 138 ANNALS OF THE MISSOURI BOTANICAL GARDEN (or 2 or 0) ; stamens 3-40; pistil 2-6-carpellary ; seeds many; endosperm 0. Reseda. (Pf. 3 2 : 237.) Family 131. Capparidaceae. Capers. Herbs, shrubs, and trees with alternate or opposite leaves, and regular or irreg- ular flowers; sepals 4; petals 4 (or 0) ; stamens 4 (or many) ; pistil 2-6-carpellary, endosperm 0. Cleome, Capparis. (Pf. 3 2 :209.) Family 132. Brassicaceae. Mustards. Herbs, rarely shrubs, with alternate (or opposite) leaves, and regular flowers ; sepals 4 ; petals 4 ; stamens 6 or 4 ; pistil 2-carpellary ; endosperm 0. Sinapis, Brassica, Raphanus, Bursa, Alyssum. (Pf. 3 2 : 145.) Order Caryophyllales. Pistil usually of 3 or more united carpels, mostly 1-celled, with a free-central placenta, and many ovules (sometimes reduced to a one-celled, one-ovuled ovary) ; stamens as many or twice as many as the petals ; flowers reg- ular; seeds mostly endospermous, usually with a curved em- bryo. ( Species about 4330. ) The general arrangement of the families of the order Caryophyllales may be understood by placing the Caryophyl- laceae centrally at the base ; from this, one line runs off to the diplochlamydeous, hermaphrodite Frankeniaceae and Tamari- caceae to the achlamydeous, diclinous Salicaceae, while on the other hand another line passes from the diplochlamydeous, many-ovuled Caryophyllaceae to the apetalous, 1-ovuled Amaranthaceae, Chenopodiaceae and Polygonaceae. Family 133. Caryophyllaceae. Pinks. Herbs (and shrubs) with opposite leaves; petals 3-5, stalked or not; ovules many on a central placenta; seeds endospermous. Silene, Lychnis, Dianthus, Alsine, Paronychia, Illecebrum. (Pf. 3 lb :61.) Family 134. Elatinaceae. Small marsh herbs or under- shrubs, with small, opposite or whorled leaves; inflorescence axillary ; petals imbricated ; stamens 4-10 ; endosperm 0. Ela- tine. (Pf. 3 6 :277.) Family 135. Portulacaceae. Purslanes. Herbs, or some- what woody plants, usually somewhat succulent, with alternate or opposite leaves; sepals usually 2; petals 4-5; seeds many, endospermous. Claytonia, Portulaca. (Pf. 3 lb : 51.) 1915] BESSEY — PHYLOGENETIC TAXONOMY 139 Family 136. Aizoaceae. Herbaceous or shrubby plants with mostly opposite or verticillate, often fleshy leaves; calyx tetramerous or pentamerous; corolla often wanting; ovary mostly 2-5-celled with few to many ovules in each cell ; seeds endospermous. Mollugo, Sesuvium, Mesembrianthemum. (Pf. 3 lb :33.) Family 137. Frankeniaceae. Herbs and undershrubs with opposite leaves, and perfect flowers ; petals 4-5, long-stalked ; ovules many, on 2-4 parietal placentae; seeds endospermous. Frankenia. (Pf. 3 8 :283.) Family 138. Tamaricaceae. Tamarixes. Shrubs and herbs with minute, alternate, deciduous leaves and mostly racemose, perfect flowers; petals 5; ovules many, on 2-5 parietal pla- centae; seeds hairy-tufted; endosperm 0. Tamarix. (Pf. 3°: 289.) Family 139. Salicaceae. Willows. Shrubs and trees with large alternate leaves and racemose flowers ; perianth ; ovules many, on 2-4 parietal placentae; seeds hairy-tufted; endo- sperm 0. Here regarded as reduced, dioecious, apetalous, Tamaricaceae. Salix, Populus. (Pf. 3 1 : 29.) Family 140. Podostemonaceae. Riverweeds. Small aquatic, sometimes thallose, plants ; flowers perfect or diclinous ; peri- anth ; pistil 1-3-celled ; ovules many, centrally attached ; en- dosperm 0. Podostemon. (Pf. 3 2a :l.) Family 141. Hydrostachydaceae. Large tuber-forming Madagascar plants, with naked, dioecious flowers, single stamens, and numerous ovules on 2 parietal placentae; en- dosperm 0. Hydrostachys. (Pf. 3 2a :22.) Family 142. Phytolaccaceae. Pokeweeds. Herbs, shrubs, and trees with usually alternate leaves; petals (or 4^5); carpels several, distinct or nearly so, 1-ovuled; seeds endo- spermous. Phytolacca. (Pf. 3 lb :l.) Family 143. Basellaceae. Herbaceous climbing plants, with mostly alternate leaves ; calyx dimerous ; corolla pentamerous ; stamens 5; ovary tricarpellary, 1-celled, with one ovule; en- dosperm scanty. Basella, Boussingaultia. (Pf. 3 la :124.) [Vol. 2 140 ANNALS OP THE MISSOURI BOTANICAL GARDEN Family 144. Amaranthaceae. Amaranths. Herbs, shrubs (and trees) with opposite or alternate leaves, and regular, mostly perfect flowers ; perianth of scarious sepds ; petals ; ovules 1 or more, basal, campylotropous ; endosperm copious. Celosia, Amaranthus, Froelichia. (Pf. 3 la : 91.) Family 145. Chenopodiaceae. The Goosefoots. Herbs, shrubs (and trees) with mostly alternate leaves, and regular, perfect or imperfect flowers; perianth of herbaceous sepals; petals 0; ovule 1, basal, campylotropous; endosperm fleshy. Beta, Chenopodium, Spinacia, Atriplex, Sarcobatus, Salsola. (Pf.3 la :36.) Family 146. Polygonaceae. Buckwheats. Herbs, shrubs, and trees with mostly alternate leaves and regular, perfect flowers ; perianth often petaloid ; petals ; pistil tricarpellary, 1-celled; ovule 1, erect, orthotropous ; endosperm copious. Eriogonum, Rumex, Rheum, Polygonum, Fagopyrum, Coc- coloba. (Pf.3 la :l.) Family 147. Nyctaginaceae. Four o 'clocks. Herbs and rarely shrubs and trees, with opposite or alternate leaves; flowers mostly perfect; petals 0; sepals often petaloid; pistil seemingly monocarpellary ; ovule 1, erect; endosperm copious to scanty. Mirabilis, Bougainvillea, Allionia. (Pf. 3 lb :14.) Family 148. Cynocrambaceae. Annual, succulent herbs, with petioled leaves, opposite below, alternate above ; flowers monoecious, apetalous, small, axillary; pistil monocarpellary; endosperm fleshy. Cynocrambe. (Pf. 3 la : 121.) Family 149. Batidaceae. Maritime shrubs with opposite fleshy leaves and small, dioecious flowers ; petals ; ovary 4- celled; ovule solitary, erect; endosperm 0. Very doubtfully placed here. Batis. (Pf. 3 la : 118.) Super-Order Strobiloideae-Sympetalae-Polycarpellatae. Carpels typically many, united; petals united. Flowers actinomorphic. Order Ebenales. Flowers regular, perfect, or diclinous; stamens mostly isomerous with, and opposite to, the corolla- lobes, or in several series ; ovary 2-many-celled ; seeds mostly 1915] BESSEY — PHYLOGEXETIC TAXONOMY 141 solitary or few, usually large, centrally attached. (Species about 1136.) Family 150. Sapotaceae. Sapodillas. Tropical trees and shrubs with a milky juice, and mostly alternate leaves ; flowers mostly perfect; sepals and petals 4-8 each; stamens in 2-3 whorls, attached to the corolla ; ovary superior, several-celled ; endosperm from fleshy to 0. Achras, Sideroxylon, Chrysophyl- lum, Mimusops. (Pf. 4 1 : 126.) Family 151. Ebenaceae. Ebonies. Tropical and subtropical trees and shrubs, with very hard wood, and mostly alternate leaves ; flowers mostly dioecious ; sepals and petals 3-7 each ; stamens usually many and free from the corolla; ovary 3- many-celled, superior ; endosperm copious. Diospyros, Maba. (Pf. 4 1 :153.) Family 152. Symplocaceae. Tropical and subtropical trees and shrubs, with mostly perfect flowers; sepals usually petals usually 5; stamens many, attached to the base of the corolla; ovary 2-5-celled, inferior; seeds few, endospermous. Symplocos. (Pf. 4 1 :165.) Family 153. Styracaceae. Styraxes. Trees and shrubs of warm climates with alternate leaves; flowers mostly perfect, sepals and petals 5 each; stamens usually many, attached to the base of the corolla; ovary 3-5-celled, usually inferior; seeds few, endospermous. Halesia, Sty rax. (Pf. 4 1 : 172.) Family 154. Fouquieriaceae. Mexican shrubs with small leaves (becoming thorn-like), and panicled tubular flowers; sepals 5; petals 5, united into a tube; stamens 10-15, free; ovary tricarpellary ; placenta central; seeds few; endosperm scanty. This small family is given place here with some con- fidence that it is much more closely related to these families than to those of the Caryophyllales and Polemoniales, with which it has been associated. Fouquieria. (Pf. 3 6 : 298.) Order Ericales. Flowers regular, perfect, pentamerous or tetramerous ; stamens alternate with the corolla-lobes, and as many or twice as many; cells of the mostly superior ovary (or placentae) 2 to many; seeds minute. (Species about 1730.) [VOL.* 2 142 ANNALS OF THE MISSOURI BOTANICAL GARDEN Family 155. Clethraceae. White alders. Shrubs and trees of warm climates, with alternate deciduous leaves and pen- tamerous flowers; stamens 10; pistil tricarpellary ; endosperm fleshy. Clethra. (Pf. 4 1 :!.) Family 156. Ericaceae. Heaths. Shrubs and small trees with mostly evergreen alternate or opposite leaves; ovary typically superior (sometimes inferior), 2-10-celled; anthers usually dehiscing by an apical pore ; endosperm fleshy. Rho- dodendron, Kalmia, Gaultheria, Arctostaphylos, Gaylussacia, Vaccinium, Calluna, Erica. (Pf. 4 1 : 15.) Family 157. Epacridaceae. Shrubs and small trees (mostly Australian) with mostly alternate evergreen leaves; ovary superior, mostly 2-10-celled; fruit capsular or drupaceous; anthers dehiscing by a slit ; endosperm fleshy. Epacris. ( Pf . 4 1 :66.) Family 158. Diapensiaceae. Low undershrubs, with alter- nate evergreen leaves; ovary superior, 3-celled; fruit a cap- sule; anthers dehiscing by a slit; endosperm fleshy. Diapen- sia, Shortia. (Pf. 4! : 80.) Family 159. Pirolaceae. Wintergreens. Low evergreen, or chlorophylless herbs, with pentamerous or tetramerous (rarely hexamerous) flowers; stamens twice as many as the petals; ovary 4-6-celled; endosperm fleshy. Pirola, Chima- phila, Monotropa. (Pf. 4 1 :3.) Family 160. Lennoaceae. Parasitic, leafless herbs; ovary superior, 10-14-carpellary, 20-28-celled ; ovules solitary ; anth- ers dehiscing by a slit; endosperm copious. Lennoa. (Pf. 4*: 12.) Order Primulales. Flowers regular, mostly perfect and pentamerous; stamens epipetalous, mostly opposite to the corolla-lobes; ovary pluricarpellary, mostly 1-celled, with a free-central placenta. (Species about 1581.) Family 161. Primulaceae. Primroses. Herbs with alter- nate or opposite leaves ; stamens attached to the upper portion of the corolla tube; pistil 2-6-carpellary, one-celled; ovules many; fruit a capsule dehiscing longitudinally from the apex, 1915] BESSEY PHYLOGENETIC TAXONOMY 143 or circumscissilely ; endosperm fleshy. Primula, Androsace, Lysimachia, Cyclamen, Dodecatheon. (Pf. 4 1 : 98.) Family 162. Plantaginaceae. Plantains. Herbs with clustered radical leaves, or alternate or opposite stem leaves ; stamens alternate with the petals; ovary mostly 2-celled; ovules many; placenta axile; fruit a capsule dehiscing circum- scissilely ; endosperm fleshy. Plantago. (Pf. 4 3b :363.) Family 163. Plumbaginaceae. Leadworts. Herbs with alternate or clustered leaves; stamens opposite the petals; pistil 5-carpellary, one-celled, with one basal, anatropous ovule; fruit capsular; dehiscence valvate or irregular; endo- sperm copious. Plumbago, Armeria. (Pf. 4 1 :116.) Family 164. Myrsinaceae. Trees and shrubs with mostly alternate leaves; stamens attached to the lower part of the corolla tube ; ovules usually few ; fruit a drupe or berry ; endo- sperm fleshy. Myrsine, Ardisia. (Pf. 4 1 : 84.) Family 165. Theophrastaceae. Tropical trees and shrubs closely related to the preceding family, and sometimes in- cluded in it, but with many ovules. Theophrasta, Jacquinia. (Pf. 4 1 :88.) S u p e r-0 r d e r Strobiloideae-Sympetalae-Dicarpellatae. Carpels typically two, united ; petals united. Flowers mostly perfect, from actinomorphic to zygomorphic. Order Gentianales. Corolla actinomorphic (regular), mostly pentamerous ; stamens alternate with the corolla-lobes, and usually of the same number and attached to the tube; leaves opposite (rarely alternate). (Species about 4664.) f Family 166. Oleaceae. Olives. Shrubs and trees (rarely herbs) with mostly opposite leaves, and tetramerous flowers; corolla-lobes mostly valvate or 0; stamens 2 (or 4); ovary 2-celled ; ovules 1-3 ; endosperm present or 0. Syringa, Olea, Jasminum, Fraxinus. (Pf. 4 2 : 1.) Family 167. Salvadoraceae. Mostly tropical shrubs and trees, with opposite undivided leaves, and tetramerous or pen- tamerous flowers; corolla-lobes imbricated; stamens 4; ovary 2-celled; ovules 2 ; endosperm 0. Salvador a. (Pf. 4 2 : 17.) [Vol. 2 144 ANNALS OF THE MISSOURI BOTANICAL GARDEN Family 168. Loganiaceae. Herbs, shrubs, and trees with mostly opposite simple leaves and pentamerous or tetramerous flowers; corolla-lobes imbricated or contorted; stamens mostly 4-5; ovary 2-celled (rarely 4-celled) ; ovules 1-many; endo- sperm fleshy. Gdsemium, Logania, Spigelia, Strychnos. (Pf. 4 2 : 19. ) Family 169. Gentianaceae. Gentians. Mostly herbs, with usually opposite undivided leaves and pentamerous or tetram- erous flowers ; corolla-lobes contorted, valvate, or induplicate ; stamens 4-5; ovary bicarpellary, usually 1-celled; ovules many; endosperm copious. Erythraea, Gentiana, Eustoma, Menyanthes. (Pf. 4 2 : 50.) Family 170. Apocynaceae. Dogbanes. Milky-juiced trees, shrubs, and herbs, with opposite or whorled, simple leaves and mostly pentamerous (rarely tetramerous) flowers; corolla-lobes contorted or valvate; stamens 5 (or 4), with granular pollen; ovary 2-celled or the carpels separating; ovules many; endosperm fleshy. Vinca, Apocynum, Nerium. (Pf. 4 2 : 109.) Family 171. Asclepiadaceae. Milkweeds. Milky- juiced herbs and shrubs, with opposite, whorled (or alternate) leaves and pentamerous flowers ; corolla-lobes contorted ; stamens 5, with agglutinated pollen; ovary of two separated carpels with one discoid stigma; ovules many; seeds usually comose; endosperm fleshy. Asclepias, Enslenia, Ceropegia, Stapelia, Hoy a. (Pf. 4 2 :189.) Order Pole moni ales. Corolla actinomorphic, becoming somewhat zygomorphic in the later families; stamens alter- nate with the corolla-lobes, of the same number and attached to the corolla tube; leaves alternate (rarely opposite). (Species about 4112.) The relationship of this order to the Primidales, and through it to the Caryophyllales, is so obvious as to make it scarcely necessary to point it out here. Family 172. Polemoniaceae. Phloxes. Herbs (and shrubs) with alternate leaves (rarely opposite below) ; flowers pentam- erous ; corolla-lobes 5, contorted ; ovary tricarpellary, 3-celled ; 1915] BESSEY — PHYLOGENETIC TAXONOMY 145 ovules 1 or more in each cell; endosperm fleshy. Cobaea, Phlox, Gilia, Polemonium. (Pf. 4 3a :40.) Family 173. Convolvulaceae. Morning-glories. Herbs (often climbing), shrubs (and trees) with alternate leaves and pentamerous flowers; corolla-limb more or less plicate (rarely imbricated); ovary 2 (3-5) -celled; ovules few; endosperm fleshy. Evolvulus, Quamoclit, Ipomoea, Convolvulus, Cus- cuta (parasitic). (Pf. 4 3a :l.) Family 174. Hydrophyllaceae. Herbs with radical or alter- nate (rarely opposite) leaves and pentamerous flowers; corolla-lobes imbricated (or contorted) ; ovary 1 or incom- pletely 2-celled ; ovules 2 or more ; endosperm fleshy. Hydro- phyllum, Phacelia, Nama. (Pf. 4 3a :54.) Family 175. Borraginaceae. Forget-me-nots. Herbs, shrubs, and trees with alternate leaves and pentamerous flowers; corolla-lobes imbricated (or contorted) ; ovary bicarpellary, 4-celled, 4-lobed; ovules solitary in each lobe; endosperm fleshy or 0. Heliotropium, Cynoglossum, Oreocarya, Borrago, Myosotis, Mertensia, Lithospermum. (Pf. 4 s *: 71.) Family 176. Nolanaceae. Herbaceous or suffrute scent pros- trate South American plants, with alternate, entire leaves; calyx 5-parted ; corolla long funnel-shaped ; stamens 5, inserted on the corolla ; carpels 5, distinct or united ; endosperm fleshy. Nolana. (Pf. 4 3b :l.) Family 177. Solanaceae. Nightshades. Herbs, shrubs (and trees) with alternate leaves and pentamerous, mostly regular, but sometimes irregular flowers; corolla-limb more or less plicate (rarely imbricated); ovary mostly 2-celled; ovules many; endosperm fleshy. Lycium, Atropa, Hyoscyamus, Physalis, Capsicum, Solanum, Datura, Nicotiana, Petunia. (Pf. 4 3b :4.) Order Scrophulariales. Corolla mostly zygomorphic (ir- regular or oblique) ; stamens fewer than the corolla-lobes, usually 4 or 2; ovules numerous; fruit mostly capsular (i. e., dehiscent). (Species about 7081.) Family 178. Scrophulariaceae. Snapdragons. Herbs (or shrubs and small trees) with alternate, opposite, or whorled 146 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 leaves ; ovary 2-celled with an axile placenta ; seeds numerous, with endosperm. Verbascum, Linaria, Antirrhinum, Maur- andia, Collinsia, Scrophidaria, Mimulus, Veronica, Digitalis, Gerardia, Castilleia, Pedicularis. (Pf. 4 3b : 39.) Family 179. Bignoniaceae. Catalpas. Trees, shrubs (and herbs) with opposite or whorled leaves; ovary 1 or 2-celled with parietal or axile placentae; seeds numerous, without endosperm. Bignonia, Catalpa, Tecoma. (Pf. 4 8b :189.) Family 180. Pedaliaceae. Mostly tropical herbs with gen- erally opposite leaves; ovary 1, 2, or 4-celled with axile pla- centae; seeds 1-many, with but little endosperm. Pedalium, Sesamum. (Pf. 4 3b :253.) Family 181. Martyniaceae. Mostly tropical herbs with generally opposite leaves; stamens 2 or 4; ovary 1-celled with projecting parietal placentae; endosperm 0. Martynia. (Pf. 4 3b :265.) Family 182. Orobanchaceae. Broom-rapes. Leafless para- sitic herbs; ovary 1-celled; placentae 4, parietal; ovules minute, numerous; endosperm fleshy. Orobanche, Thalesia, Conopholis. (Pf. 4 3b :123.) Family 183. Gesneraceae. Tropical and subtropical herbs, shrubs (and trees) with usually opposite leaves; ovary in- ferior or superior, 1-celled, with 2 parietal placentae; seeds numerous; endosperm scanty or 0. Streptocarpus, Gesnera, Gloxinia. (Pf. 4 3b : 133.) Family 184. Columelliaceae. South American trees and shrubs with opposite, evergreen leaves and nearly regular flowers ; stamens 2 ; ovary inferior, 2-celled, with an axile pla- centa; endosperm fleshy. Columellia. (Pf. 4 3b :186.) Family 185. Lentibulariaceae. Bladderworts. Aquatic or marsh herbs with basal, entire or dissected leaves and irreg- ular flowers; ovary 1-celled, with a globose basilar placenta; seeds numerous ; endosperm 0. Pinguicula, Utricularia. (Pf. 4 3b :108.) Family 186. Globulariaceae. Shrubs and undershrubs or evergreen herbs, with alternate leaves, and a terminal capitate 1915] BESSEY — PHYLOGENETIC TAXONOMY 147 cluster of small irregular flowers ; ovary 1-celled, with a single ovule; endosperm fleshy. Globularia. (Pf. 4 3b :270.) Family 187. Acanthaceae. Herbs (shrubs and trees) with opposite leaves; ovary 2-celled; placentae axile; fruit a dry pod which splits open vertically ; seeds 2-many, without endo- sperm. Thuribergia, Ruellia, Acanthus, Justicia. (Pf. 4 3b :274.) Order Lamiales. Corolla mostly zygomorphic (irregular or oblique) ; stamens fewer than the corolla-lobes, usually 4 or 2; ovules mostly 2 in each carpel; fruit indehiscent. (Species about 4119.) Family 188. Myoporaceae. Mostly Australasian shrubs and trees, with usually alternate leaves ; flowers axillary ; fruit a 1-4-seeded drupe; endosperm scanty. Myoporum. (Pf. 4 3b : 354. ) Family 189. Phrymaceae. Erect, perennial herbs, with opposite leaves, and small spicate flowers; calyx and corolla cylindrical, 2-lipped; stamens 4; ovary 1-celled, 1-ovuled; stigma bifid; endosperm 0. Phryma. (Pf. 4 3b : 361.) Family 190. Verbenaceae. Verbenas. Herbs, shrubs, and trees, with usually opposite leaves; ovary of 2 carpels, but 2-8-celled, with 1 ovule in each cell ; stigma usually undivided ; endosperm scanty or 0. Verbena, Lantana, Lippia, Tectona, Vitex. (Pf. 4 3a :132.) Family 191. Lamiaceae. Mints. Mostly aromatic herbs, shrubs (and trees) with opposite or whorled leaves; ovary 4-celled, 4-lobed with 1 ovule in each cell ; stigma usually bifid ; endosperm scanty or 0. Lavendula, Nepeta, Stachys, Salvia, Thymus, Mentha, Coleus. (Pf. 4 3a : 183.) With this order {Lamiales), and especially with this family {Lamiaceae), we attain the summit of the cone-flowers {Stro- biloideae). We next return almost to the point of beginning, and there start on a new phyletic line. Sub-Class OPPOSITIFOLIAE - COTYLOIDE AE. < * Cup Flowers. ' ' Axis of the flower normally expanded into a disk or cup, bearing on its margin the perianth and stamens (or the latter may be attached to the corolla). [Vol. 148 ANNALS OF THE MISSOURI BOTANICAL GARDEN Super-Order Cotyloideae - Apopetalae. Petals separate. Carpels many to few, separate to united, superior to inferior. This super-order appears to have originated near the begin- ning of the Strobiloideae, and therefore the orders Ranales and Rosales are to be regarded as closely related. Their relationship to Alismatales, also, has already been pointed out. Order Rosales. Flowers cyclic, usually perfect, dichlamy- deous (rarely apetalous), actinomorphic to zygomorphic (regular to irregular) and mostly pentamerous; carpels usually several to many, separate or more or less united, some- times united with the axis-cup (rarely reduced to 1) ; styles usually distinct. (Species about 14261.) Family 192. Rosaceae. Roses. Herbs, shrubs, and trees with mostly alternate leaves; stamens usually indefinite, on the cup-margin; carpels several to many (rarely 1), free (but they may be enclosed in the deep cup) ; ovules usually 2, ana- tropous; endosperm 0. Potentilla, Frag aria, Spiraea, Rosa. ( Species about 2700. ) ( Pf . 3 ! : 1. ) Family 193. Malaceae. Apples. Shrubs and trees with alternate leaves; stamens usually many on the cup-margin; carpels few, more or less united, and adnate to the axis-cup, so as to be "inferior"; endosperm 0. Sorbus, Pirus, Mains, Crataegus. (Pf. 3 :{ :1, 18.) Family 194. Prunaceae. Plums. Shrubs and trees with alternate leaves; stamens many, on the cup-margin; carpel one, in the bottom of the dee]) cup, becoming a drupe; endo- sperm 0. Prunus, Amygdalus. (Species 150.) (Pf. 3 3 : 1, 50.) Family 195. Crossosomataceae. Southwest North American shrubs, with small leaves and a bitter bark ; sepals and petals 5 each; stamens 20 or more; carpels 3-5; seeds many, reni- I'orm; endosperm scanty. Crossosoma. (Pf. Nachtrage zu Teil ii-iv, 185.) Family 196. Connaraceae. Tropical trees and shrubs with alternate compound leaves; stamens definite (5-10); mostly 5, free; ovules 2, ascending, orthotropous ; endosperm fleshy or 0. Connarus, Cnestis. (Pf. 3 3 :61.) 1915] BESSEY rilYLOGENETIC TAXONOMY 149 Family 197. Mimosaceae. The mimosas. Mostly tropical trees, shrubs, and herbs, with alternate mostly compound leaves; flowers actinomorphic ; stamens 10 or more, usually separate ; carpel 1 ; fruit a legume ; seeds mostly without endo- sperm. Acacia, Mimosa. (Species 1483.) (Pf. 3 3 : 70, 99.) Family 198. Cassiaceae. The sennas. Mostly tropical trees, shrubs, and herbs, with alternate mostly compound leaves; flowers zygomorphic; stamens 10 or less, usually sepa- rate; carpel 1; fruit a legume; seeds with or without endo- sperm. Cassia, Caesalpinia, Gleditsia, Gymnocladus. (Species 1172.) (Pf. 3 3 : 70, 125.) Family 199. Fabaceae. The beans. Mostly herbs of tem- perate climates, but with many shrubs and trees ; leaves alter- nate, mostly compound; flowers zygomorphic; stamens 10 or less, usually more or less united; carpel 1; fruit a legume; seeds usually without endosperm. Lupinus, Medicago, Tri- folium, Robinia, Astragalus, Arachis, Vicia, Pisum, Phaseolus. (Species 6948.) (Pf. 3 3 :70, 184.) This family constitutes a well-marked side-line in the order Rosales, with zygomorphic, entomophilous flowers. It is not obvious what relation, if any, exists between this form of the flower, and the legume structure of the fruiting carpel. Family 200. Saxifragaceae. Saxifrages. Herbs with alter- nate leaves, regular 4 or 5-merous mostly perfect flowers, with 8 or 10 stamens, and usually 2 more or less united carpels which are superior; seeds many; endosperm copious. Saxi- fraga, Heuchera, Mitella. (Pf. 3 2a : 41.) Family 201. Hydrangeaceae. Hydrangeas. Shrubs and trees with mostly opposite leaves, and regular 4 or 5-merous mostly perfect flowers, with few (8) to many (40) stamens, and 2-5 united carpels, which are more or less overgrown by the axis-cup ; seeds many ; endosperm copious. Philadelphus , Hydrangea. (Pf. 3 2a :41.) Family 202. Grossulariaceae. Gooseberries. Shrubs with alternate leaves, regular 4 or 5-merous perfect flowers, usually 5 stamens, and 2 to several united carpels which are wholly [Vol. 2 150 ANNALS OP THE MISSOURI BOTANICAL GARDEN overgrown by the fleshy cup (ovary inferior) ; seeds few, endo- sperm copious. Ribes. (Pf. 3 2a : 41.) Family 203. Crassulaceae. Stonecrops. Mostly fleshy herbs, with opposite or alternate leaves and perfect flowers; stamens definite (4-10 or many) ; pistils several, free or little united; ovules many; placentae central or axile; endosperm fleshy. Sedum, Cotyledon, Crassula, Penthorum. (Pf. 3 2a : 23.) Family 204. Droseraceae. Sundews. Gland-bearing marsh herbs with perfect flowers; stamens mostly definite (4-20); pistil syncarpous, 1-3-celled, superior; ovules many, on basal, axile, or parietal placentae; endosperm fleshy. Drosera, Dionaea. (Pf. 3 2 :261.) Family 205. Cephalotaceae. Pitcher-plants. Perennial Australian herbs with a rosette of elliptic, and pipe-shaped radical leaves, and a central, erect, spicate flowering stem; flowers regular, perfect, apetalous; sepals 6; ovules solitary; endosperm copious. Cephalotus. (Pf. 3 2 ": 39.) Family 206. Pittosporaceae. Trees and shrubs of the southern hemisphere, with alternate leaves ; sepals, petals, and stamens 5 each ; ovary 2-carpellate ; endosperm copious. Pitto- sporum, Marianthus. (Pf. 3 2a :106.) Family 207. Brunelliaceae. South American trees, with opposite or whorled leaves and diclinous flowers; sepals and petals 4-5 or 7 each; stamens twice as many; carpels usually 4-5, free; endosperm fleshy. Brunellia. (Pf. Nachtrage zu Teiln-iv, 182.) Family 208. Cunoniaceae. Shrubs and trees, mostly of the southern hemisphere, with opposite or whorled leaves and small, perfect flowers; sepals and petals 4-6 each; stamens twice as many; carpels 2-5, united; endosperm fleshy. Belangera, Cunonia. (Pf. 3 2a : 94.) Family 209. Myrothamnaceae. Small, rigid, balsamic South African and Madagascar shrubs, with opposite leaves, and dioecious, achlamydeous flowers; ovary tricarpellary ; seeds many, with fleshy endosperm. Myrothamnus. (Pf. 3 2a :103.) 1915] BESSEY PHYLOGENETIC TAXONOMY 151 Family 210. Bruniaceae. Heath-like shrubs of the southern hemisphere, with small leaves and small, perfect, regular, pentamerous flowers; stamens definite; pistil 2-3-celled, in- ferior or superior; ovules 1 to many, pendulous; endosperm copious. Brunia. (Pf. 3 2a : 131.) Family 211. Hamamelidaceae. Witch-hazels. Shrubs and trees with mostly alternate leaves and perfect or imperfect, mostly pentamerous flowers; stamens few or many; pistil bicarpellary, its ovary inferior ; ovules solitary or many ; endo- sperm thin. Liquidambar, Altingia, Hamamelis. (Pf. 3 2a :115.) Family 212. Casuarinaceae. Beefwood trees. Shrubs and trees with striate stems bearing whorls of reduced scale-like leaves ; flowers diclinous ; petals ; pistil bicarpellary, 1-celled ; ovules 2, lateral, half anatropous; endosperm 0. Casuarina. (Pf. 3 1 : 16.) This family, which has puzzled botanists from the first, is doubtfully placed here, on the theory that these plants are leafless relatives of the Hamamelidaceae. Family 213. Eucommiaceae. Chinese trees, with alternate leaves, and achlamydeous diclinous flowers; stamens 6-10; pistil bicarpellary, 1-celled, 2-seeded; endosperm present. Eucommia. (Pf. Nachtrage zu Teil ii-iv, 159.) Family 214. Platanaceae. Plane-trees. Trees with alter- nate leaves, and monoecious flowers in globular heads ; peri- anth 3-8-merous; stamens 3-8; pistils 3-8, each 1-celled, 1-ovuled; endosperm scanty. Plat anus. (Pf. 3 2a :137.) Order Myktales. Flowers usually actinomorphic (regular) or nearly so, usually perfect ; pistil of united carpels, usually inferior; placentae axile or apical (rarely basal); style 1 (rarely several) ; leaves simple, usually entire. (Species about 7323.) Here again we shall soon reach the end of a phyletic side- line, consisting principally of the order Myrtales, with the Loasales and Cactales as the ultimate branches. Family 215. Lythraceae. Herbs, shrubs, and trees usually with opposite leaves and 4-angled branches; flowers mostly 4-6-merous; stamens definite (8-12), or indefinite; pistil 2-6- [Vol. 2 152 ANNALS OF THE MISSOURI BOTANICAL GARDEN celled, free ; ovules numerous, on axile placentae ; endosperm 0. Lythrum, Cuphea, Lag erst roemia. (Pf. 3 7 :1.) Family 216. Sonneratiaceae. Tropical trees with opposite leaves; ovary sunken in the axis-cup, many celled (4-15); stamens many; endosperm 0. Sonneratia. (Pf. 3 7 :16.) Family 217. Punicaceae. Pomegranates. Small tropical and sub-tropical trees with opposite leaves and 5-7-merous flowers; stamens many; ovary inferior, 4- 15-celled, producing a pulpy, many-seeded fruit; endosperm 0. Punica. (Pf. 3 7 :22.) Family 218. Lecythidaceae. Tropical trees, with alternate leaves and usually 4- 6-merous flowers ; stamens many ; ovary inferior, 2-6-celled; endosperm 0. Barringtonia, Napoleona, Lecythis, Bertholletia. (Pf. 3 7 :26.) Family 219. Melastomataceae. Mostly tropical herbs, shrubs, and trees with generally opposite or whorled leaves; stamens usually double the number of petals; pistil 2-many- celled, inferior; ovules minute, numerous, on axile or parietal placentae; endosperm 0. Melastoma, Osbeckia, Rhexia, Tamonea. (Pf. 3 7 :130.) Family 220. Myrtaceae. Myrtles. Trees and shrubs with opposite or alternate leaves, and perfect, regular flowers; stamens many; pistil 2-many-celled, inferior; ovules 2 to many; plancentae basal or axile; endosperm 0. Myrtus, Pimbnta, Eugenia, Jambosa, Eucalyptus, Malaleuca. (Species 2556.) (Pf. 3 7 :57.) Family 221. Combretaceae. Trees and shrubs often (limb- ing, with opposite or alternate leaves ; stamens usually definite (4-10); pistil 1-celled, inferior; ovules 2-6 or solitary, pen- dulous; endosperm 0. Terminalla, Combretum, Laguncularia. (Pf. 3 7 :106.) Family 222. Rhizophoraceae. Mangroves. Mostly tropical trees and shrubs with opposite leaves and regular, 4^8-merous flowers; stamens 2-A times the number of petals; pistil 2-6- celled, usually inferior; ovules 2, pendulous; endosperm fleshy. BMzophora, CaraUla. (Pf. 3 7 :42.) 1915] BESSEY — PHYLOGENETIC TAXONOMY 153 Family 223. Oenotheraceae. Evening primroses. Herbs (shrnbs and trees) with opposite or alternate leaves, and perfect, 2-3^-merous, regular flowers; stamens 1-8, rarely more; pistil usually 4-celled, inferior; ovules 1 to many on axile placentae; endosperm scanty or 0. Epilobium, Anogra, Oenothera, Meriolix, Gaura, Fuchsia, Circaea. (Pf. 3 7 :199.) Family 224. Halorrhagidaceae. Aquatic or terrestrial herbs with opposite or alternate leaves and perfect or im- perfect, sometimes apetalous flowers; pistil 1-4-celled, in- ferior; ovules solitary, pendulous; endosperm present. Hal- orrhagis, Myriophyllum. (Pf. 3 7 : 226.) Family 225. Hippuridaceae. Aquatic perennial erect herbs, with whorled leaves, and small, reduced, axillary apetalous flowers; ovary 1-celled, 1-ovuled; endosperm scanty. Hip- puris. (Pf. 3 7 :237.) Family 226. Cynomoriaceae. Parasitic rhizomatous fleshy plants with spicate, small, apetalous, diclinous flowers, each with a single ovule; endosperm fleshy. Cynomorium. (Pf. 3 1 :250.) Family 227. Aristolochiaceae. Dutchman 's-pipes. Her- baceous or shrubby plants, with alternate leaves and large, apetalous, perfect, irregular flowers ; stamens 6, rarely more ; pistil 4 or 6-celled, inferior; ovules numerous, on axile (or protruding parietal) placentae; endosperm copious. Asarum, Aristolochia. (Pf. 3 1 : 264.) Family 228. Rafflesiaceae. Fleshy, parasitic herbs, of warm climates, leafless, or nearly so, with mostly imperfect flowers ; petals 0, or rarely 4; stamens 8 to many; pistil 1-celled or imperfectly many-celled, inferior; ovules minute, very num- erous, on parietal or pendulous, folded placentae ; endosperm present. Rafflesia, Cytinus. (Pf. 3 1 :274.) Family 229. Hydnoraceae. Parasitic, succulent, tropical herbs with perfect, 3-4-merous flowers; perianth single, val- vate; stamens 3^4, but anthers many; seeds very numerous; endosperm copious. Hydnora. (Pf. 3 1 :282.) [Vol. 2 154 ANNALS OF THE MISSOURI BOTANICAL OAKDEN Order Loasales. Flowers usually actinomorphic, perfect or diclinous ; pistil mostly tricarpellary, 1-celled, its ovary usually inferior ; placentae parietal and with many ovules ; styles free or connate; leaves ample, entire, lobed or dissected. (Species about 1392.) Family 230. Loasaceae. Star-flowers. Herbs (rarely climbing) with opposite or alternate leaves; flowers perfect; sepals and petals dissimilar, mostly 5 each ; stamens indefinite, 5-10 or more; ovary 3-7-carpellary, 1-celled; endosperm mostly 0. Mentzelia, Loasa. (Pf. 3 e M00.) Family 231. Cucurbitaceae. Melons. Mostly climbing or prostrate herbs and undershrubs, with alternate leaves; flowers mostly diclinous and pentamerous; stamens definite (usually 3) ; ovary mostly tricarpellary; endosperm 0. Melo- thria, Momordica, Luff a, Citrullus, Cucumis, Lagenaria, Cucurbita. (Pf. 4 r> : 1.) Family 232. Begoniaceae. Begonias. Mostly erect herbs with alternate leaves; flowers diclinous, more or less zygo- morphic; stamens indefinite and numerous, ovary tricar- pellary, 3-celled, usually 3-angular; endosperm little or 0. Begonia. (Pf. 3 6a : 121.) Family 233. Datiscaceae. Herbs or large trees, with alter- nate leaves ; flowers small, and diclinous ; stamens 4 to many ; ovary 3-8-carpellary ; placentae on the walls; seeds small, and many; endosperm scanty. Datisca. (Pf. 3 6a : 150.) Family 234. Ancistrocladaceae. Climbing plants of tropical Asia, with alternate leaves, and small, regular, perfect flowers; petals 5; stamens 5-10; ovary 1-celled, many-se< endosperm present. Ancistrocladus. (Pf. 3 6 : 274.) Order Cactales. Flowers actinomorphic or very slightly zygomorphic, perfect; stamens many; pistil 4-8-carpous, in- ferior, 1-celled, with 4-8 parietal placentae ; style single, with 2 to many stigmas; endosperm scanty or 0; embryo curved. Fleshy-stemmed plants with leaves mostly small or wanting. (Species about 1168.) Family 235. Cactaceae. Cactuses. Mostly natives of the warmer -portions of America; from small herbs to tree-like ded 1915] BESSEY PHYLOGENETIC TAXONOMY 155 dimensions. Peireskia, Opuntia, Cereus, Carnegiea, Echino- cactus, Melocactus, Cactus, Rhipsalis. (Pf. 3 6a :156.) Order Celasteales. Keceptacle often developing a gland- ular, annular or turgid disk, which is sometimes adnate to the pistil, in which case the pistil is more or less inferior ; pistil 1 to many-celled (rarely apocarpous) ; ovules 1-3, pendulous or erect; endosperm present or 0. Flowers actinomorphic and mostly perfect. (Species about 2741.) Family 236. Rhamnaceae. Buckthorns. Trees and shrubs often climbing, with alternate or opposite, simple leaves; petals present ; disk more or less adnate to the 2-4-celled pistil ; ovules 1 or 2, erect; endosperm fleshy. Zizyphus, Rhamnus, Ceanothus, Phylica, Colletia. (Pf. 3 5 :393.) Family 237. Vitaceae. Grapes. Climbing shrubs (and trees) with alternate, simple or compound leaves ; petals coher- ent, valvate; pistil superior, 2-celled, 2-ovuled (or 3-6-celled, 1-ovuled) ; endosperm often ruminate. Vitis, Parthenocissus, Cissus. (Pf. 3 5 :427.) Family 238. Celastraceae. Bittersweets. Shrubs (often climbing) and trees, with usually alternate, simple leaves; petals present, imbricated; disk more or less adnate to the 2-5-celled pistil; ovules usually 2, erect or pendulous; endo- sperm fleshy. Euonymus, Celastrus, Cassine. (Pf. 3 5 : 189.) Family 239. Buxaceae. Boxes. Evergreen shrubs and trees, with alternate or opposite leaves, and usually monoe- cious, small, apetalous flowers ; stamens 4 ; pistil tricarpellary, superior; endosperm fleshy. Pachysandra, Buxus. (Pf. 3 5 :130.) Family 240. Aquifoliaceae. Hollies. Trees and shrubs, with alternate or opposite, simple leaves and small, perfect flowers ; pistil superior, 3 to many-celled ; ovule 1, pendulous ; endosperm fleshy. Ilex, Nemo panthes. (Pf. 3 5 :183.) Family 241. Cyrillaceae. South American evergreen shrubs or small trees, with alternate leaves ; sepals 5 ; petals 5 ; stamens 5-10 ; carpels 2-5, united, superior ; endosperm fleshy. Cy villa. (Pf. 3 5 :179.) IVol. 2 156 ANNALS OF THE MISSOURI BOTANICAL GARDEN Family 242. Pentaphylacaceae. Chinese trees, with alter- nate, leathery leaves and small, perfect flowers; sepals 5; petals 5 ; stamens 5 ; pistil superior, of 5 carpels, each 2-ovuled; endosperm scanty. Pentaphylax. (Pf. Nachtrage zu Teil ii-iv, 214.) Family 243. Corynocarpaceae. New Zealand trees, with alternate, fleshy, leathery leaves ; sepals 5 ; petals 5 ; stamens 5; pistil superior, of 2 carpels; endosperm 0. Corynocarpus. (Pf. Nachtrage zu Teil ii-iv, 215.) Family 244. Hippocrateaceae. Tropical trailing and climbing woody plants with opposite leaves ; sepals 5 ; petals 5; stamens 3 or 2 or 5; pistil of 3 carpels more or less adnate to the disk; endosperm 0. Hippocratea, Salacia. (Pf. 3 5 : 222.) Family 245. Stackhousiaceae. Australian herbs and shrubs with simple alternate leaves and perfect flowers; petals stamens 5 ; ovary 2-5-celled ; ovule 1 in each cell, erect ; endo- sperm fleshy. Stackhousia. (Pf. 3 r> : 231.) Family 246. Staphyleaceae. Bladder-nuts. Erect shrubs and trees, with opposite, compound leaves and pentamerous perfect flowers; sepals 5; petals 5; stamens 5; pistil of 2-3 superior carpels ; seeds few to many ; endosperm fleshy or 0. Staphylea, Turpinia. (Pf. 3 8 : 258.) Family 247. Geissolomataceae. South African evergreen shrubs, with opposite sessile leaves; sepals 4; petals none; stamens 8; pistil superior, of 4 carpels, each 2-ovuled; endo- sperm fleshy. Gcissoloma. (Pf. 3 0a : 205.) Family 248. Penaeaceae. South African evergreen heath- like shrubs, with small, opposite leaves and regular, perfect flowers; petals 0; pistil superior, 4-celled; ovules 2-4, erect; endosperm 0. Penaea. (Pf. 3 0a : 208.) Family 249. Oliniaceae. African shrubs and trees, with thick, leathery, opposite leaves, and small, regular, perfect flowers; sepals 4-5, large; petals 4-5, very small; stamens 4-5 ; pistil inferior, of 3-5 carpels ; endosperm 0. Olinia. (Pf. 3 6a :213.) Family 250. Thymelaeaceae. Shrubs, small trees (and herbs), with alternate or opposite, usually coriaceous, simple 1915] BESSEY — PHYLOGEXETIC TAXONOMY 157 leaves and small petalous or apetalous, mostly perfect flowers ; pistil superior, 1-5-carpellary, 1-celled; ovule 1, pendulous; endosperm fleshy, sparse, or 0. Gnidia, Thymelaea, Daphne, Dirca. (Pf. 3 Ga :215.) Family 251. Hernandiaceae. Tropical trees and shrubs, with alternate leaves ; flowers perfect or monoecious, regular ; sepals 4-10; petals none; stamens 3; pistil 1-celled, inferior; ovule 1, pendulous; endosperm 0. Hernandia. (Pf. 3 2 : 126.) Family 252. Elaeagnaceae. Oleasters. White or brown- scurfy trees and shrubs, with alternate or opposite, simple leaves and perfect or diclinous flowers ; petals ; pistil 1-celled ; ovule 1, ascending; endosperm or scanty. Elaeagnus, Lepargyraea. (Pf. 3 Ga : 246.) Family 253. Myzodendraceae. South American parasitic shrubs, with alternate, rather small leaves ; flowers dioecious, apetalous; stamens 2-3; pistil 1-celled, inferior; endosperm fleshy. Myzodendron. (Pf. Z 1 :!^.) Family 254. Santalaceae. Sandalwoods. Parasitic herbs, shrubs, and trees, with alternate or opposite, simple leaves and small, perfect, or diclinous flowers; epigynous; petals 0; pistil inferior, 1-5-carpellary, 1-celled ; ovules 2-5, pendulous ; endosperm present. Santalum, Comandra, Thesium. (Pf. 3!:202.) Family 255. Opiliaceae. Shrubs of tropical climates, with alternate leaves, and perfect flowers; sepals, petals and sta- mens 4-5 each; pistil superior, 1-celled, 1-ovuled; endosperm fleshy. Opilia. (Pf. Nachtrage zu Teil ii-iv, 142.) Family 256. Grubbiaceae. South African shrubs with op- posite leaves, and epigynous, apetalous flowers ; ovary 2-celled ; ovules 2 ; endosperm fleshy. Grubbia. (Pf. 3 1 : 282.) Family 257. Olacaceae. Trees and shrubs, often twining, mostly tropical, with usually alternate, simple leaves and mostly perfect, apetalous flowers; pistil superior or inferior, 1-3-celled; ovules 2-3, pendulous; endosperm fleshy. Olax. (Pf. 3 1 :231.) Family 258. Loranthaceae. Mistletoes. Parasitic ever- green shrubs with opposite (or alternate) leaves, often re- [Vol. 2 158 ANNALS OF THE MISSOURI BOTANICAL GARDEN duced to bracts ; flowers perfect or diclinous ; petals ; pistil 1-celled, inferior; ovule 1, erect; endosperm fleshy. Loranthus, Viscum, Phoradendron, Razoumowskia. (Pf. 3 1 :156.) Family 259. Balanophoraceae. Parasitic, leafless herbs, all tropical, with much reduced, apetalous, monoecious or dioecious flowers; pistil 1-celled, inferior; ovule 1, pendulous; endosperm fleshy. Balanophora. (Pf. 3 1 :243.) Order Sapindales. Flowers mostly actinomorphic, perfect, or diclinous; pistil 1 to several-celled, superior to inferior; ovules 1-2, erect, ascending, or pendulous ; endosperm mostly 0. (Species about 2903.) The Sapindales lie wholly in a phyletic side-line, and the order has been developed from some part of the intermediate order Celastrales, which constitutes a transition from the lower hypogynous cup flowers to those in which epigyny is fixed. In the lower Sapindales hypogyny still persists, but in the higher families this gives way to complete epigyny. Family 260. Sapindaceae. Soapberries. Trees and shrubs, mostly tropical, with alternate (or opposite), mostly com- pound leaves and mostly perfect, irregular flowers; disk pres- ent or 0; petals 3-5 or 0; pistil 1-3-celled; ovules 1 or ascending ; endosperm usually 0. Paullinia, Sapindus, Talisia, Litchi, K o elr eut eria , Dodonaea. (Pf. 3 5 : 277.) Family 261. Hippocastanaceae. Horsechestnuts. Trees and shrubs, with opposite, palmately compound leaves ; flowers mostly regular; sepals 5; petals 4-5; stamens 8-5; pistil su- perior, tricarpellary ; endosperm 0. Aesculus. (Pf. 3 8 : 273.) Family 262. Aceraceae. Maples. Trees and shrubs, with opposite, simple or compound leaves and small, regular flow- ers ; sepals 4-10 ; petals as many or none ; pistil superior, bi- carpellary, winged in fruit; endosperm 0. Acer. (Pf. 3 5 : 258.) Family 263. Sabiaceae. Trees and shrubs of the tropics, with alternate, simple or compound leaves, and perfect or diclinous flowers ; petals 4-5 ; pistil 2-3-celled ; ovules 1 or 2, horizontal or pendulous; endosperm 0. Sabia, Meliosma. (Pf. 3 5 :367.) 1915] BESSEY PHYLOGENETIC TAXONOMY 159 Family 264. Icacinaceae. Tropical trees and shrubs, with alternate or opposite leaves and regular, perfect or diclinous flowers ; sepals 5 ; petals 5 ; stamens 5 ; pistil superior, 1-celled, and tricarpellary ; endosperm fleshy. Icacina. (Pf. 3 5 : 233.) Family 265. Melianthaceae. Tropical trees and shrubs, with alternate leaves, and pentamerous, mostly perfect, zygo- morphic flowers ; endosperm fleshy. Melianthus. (Pf. 3 5 : 374.) Family 266. Empetraceae. Heath-like shrubs, with small alternate leaves; flowers small, regular, mostly dioecious, solitary or in heads ; petals present ; stamens 2-3, 2-3-celled ; pistil 2 to many-celled ; seeds solitary, endospermous. Corema, Empetrum. (Pf. 3 5 :123.) Family 267. Coriariaceae. Shrubs with opposite, sessile leaves and perfect or diclinous flowers ; 5 sepals ; 5 petals ; 10 stamens ; 5-10 carpels, slightly united ; seeds few ; endosperm scanty. Coriaria. (Pf. 3 5 :128.) Family 268. Anacardiaceae. Sumachs. Trees and shrubs, mostly tropical, with alternate, usually compound leaves and small, perfect flowers; petals 3-7 or 0; pistil 1-5-celled, superior, but surrounded by the fleshy cup; ovules solitary, pendulous (or erect) ; endosperm 0. Mangifera, Anacardium, Schinus, Cotinus, Metopium, Rhus. (Pf. 3 5 : 138.) Family 269. Juglandaceae. Walnuts. Trees and shrubs, with alternate, compound leaves and small, diclinous, apet- alous flowers ; pistil bicarpellary, 1-celled, adnate to the fleshy cup, and so inferior ; ovule 1, erect, orthotropous ; endosperm 0. Engelhardtia, Juglans, Hicoria. (Pf. 3 X :19.) Family 270. Betulaceae. Birches. Trees and shrubs, with alternate, simple leaves, and monoecious or dioecious flowers, which are in aments; petals none; calyx small or none; sta- mens 2-10 ; pistil inferior, bicarpellary, 1-2-celled ; endosperm 0. Carpinus, Ostrya, Corylus, Betula, Alnus. (Pf. 3 1 : 38.) Family 271. Fagaceae. Beeches. Trees and shrubs, with alternate, simple leaves and small, diclinous flowers ; petals ; pistil mostly tricarpellary, 2-6-celled, inferior; ovules 2 in each cell, erect or pendulous; fruit usually 1-seeded; endo- sperm 0. Fagus, Castanea, Pasania, Quercus. (Pf. 3 1 :47.) < 160 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 Family 272. Myricaceae. Bay berries. Shrubs and trees, with alternate, simple leaves and small, achlamydeous, diclinous flowers; petals 0; pistil free, bicarpellary, 1-celled; ovule 1, erect, orthotropous; endosperm 0. Myrica. (Pf. V:26.) Family 273. Julianaceae. Dioecious, tropical trees, with alternate leaves; flowers small, apetalous, dioecious; stamens 4-8; pistil of 3-5 carpels; endosperm 0. Juliana. (Pf. Nach- trage zu Teil ii-iv, 335, and Syllabus, 161.) This family is given place here very doubtfully. Family 274. Proteaceae. Shrubs, trees (and herbs) of the southern hemisphere, with mostly alternate, simple, usually coriaceous, evergreen leaves; flowers perfect or diclinous; sepals petaloid; petals 0; stamens 4; pistil monocarpellary, 1-celled ; ovule 1, erect or pendulous ; endosperm little or none. Protea, Leucadendron, Grevillea, Hakea, Banksia. (Pf. 3 1 : 118.) This puzzling family is given place here very doubtfully. Order Umbellales. Flowers actinomorphic (regular), usually perfect, 4-5-merous; calyx small to minute; stamens usually definite (4-5) ; pistil syncarpous, 1 to many-celled, its ovary inferior; ovules solitary, pendulous; styles free or united at the base ; endosperm copious ; embryo usually minute. (Species about 2809.) Family 275. Araliaceae. Aral i as. Trees, shrubs (and herbs), mostly tropical, with alternate leaves; flowers in umbels, heads, or panicles; ovary 2-15-celled; fruit a berry with a fleshy or dry exocarp. Hedera, Aralia, Panax. (Pf. 3 8 :1.) Family 276. Apiaceae. Parsleys. Herbs (shrubs and trees), with alternate leaves; flowers small, pentamerous, mostly umbellate; ovary 2-celled; fruit splitting into two dry indehiscent mericarps. Hydrocotyle, Sanicula, Eryngium, Coriandrum, Conium, Apium, Cicuta, Carum, Foeniculum, Angelica, Ferula, Heracleum, Daucus. (Species 2177.) (Pf. 3*: 63.) Family 277. Cornaceae. Cornels. Shrubs and trees (rarely herbs), with usually opposite leaves; flowers larger, 4-5- 1915] BESSEY PHYLOGENETIC TAXONOMY 161 merous, umbellate, capitate, or corymbose; ovary 2-4-celled, fruit drupaceous. Garrya, Nyssa, Cornus, Aucuba. (Pf. 3 8 :250.) Super-Order Cotyloideae - Sympetalae. Petals united. Carpels few, united, inferior ; stamens usually as many as the corolla-lobes, mostly attached to the corolla. Order Bubiales. Flowers 4-5-merous, actinomorphic (rarely zygomorphic) ; stamens 4-5, attached to the corolla; calyx small ; ovary 2-8-celled ; ovules 2 to many in each cell. (Species about 5063.) Family 278. Rubiaceae. Madders. Trees, shrubs and herbs, mostly tropical, with opposite or whorled leaves ; flowers usually perfect, and regular, with valvate, contorted, or im- bricate corolla-lobes ; carpels mostly 2 ; style simple, bifid, or multifid; fruit a capsule, berry, or drupe; endosperm from fleshy to 0. Houstonia, Cinchona, Bouvardia, C ephalanthus , Randia, Coffea, Mitchella, Galium, Rubia. (Pf. 4 4 :1.) Family 279. Caprifoliaceae. Honeysuckles. Mostly woody plants with opposite leaves ; flowers usually zygomorphic, with imbricate corolla-lobes ; carpels 2-5, with 1 or more pendulous ovules; style usually with a capitate undivided stigma; fruit a berry; endosperm fleshy. Sambucus, Viburnum, Linnaea, Lonicera. (Pf. 4 4 :156.) Family 280. Adoxaceae. Moschatels. Slender herbs with scaly rootstocks, bearing ternately compound leaves; flowers small, regular, greenish, in heads; stamens about 10; ovary 3-5-celled; fruit drupaceous; endosperm cartilaginous. Adoxa. (Pf. 4 4 :170.) Family 281. Valerianaceae. Valerians. Herbs (and shrubs) with opposite leaves; flowers somewhat irregular, cymose, corymbose, or solitary; stamens 1-4, the anthers free; ovary 1-3-celled, the ovules pendulous; fruit with 1 fertile cell, 1-seeded; endosperm scanty, or 0. Valerianella, Fedia, Valeriana. (Pf. 4 4 :172.) Family 282. Dipsacaceae. Teasels. Herbs (and shrubs) with opposite or whorled leaves; flowers zygomorphic, in [Vol. 2 162 ANNALS OF THE MISSOURI BOTANICAL GARDEN involucrate heads; stamens 2-4, the anthers free; carpels 2, but pistil 1-celled; ovule 1, pendulous; endosperm scanty. Cephalaria, Dipsacus, Scabiosa. (Pf. 4 4 : 182.) Order Campanulales. Flowers actinomorphic to zygo- morphic; stamens mostly free, their anthers free or connate; ovary 1 to several-celled; ovules 1-8. (Species about 1539.) Family 283. Campanulaceae. Bellflowers. Mostly milky- juiced herbs (shrubs and small trees), with alternate (or oppo- site) leaves; flowers regular or irregular; stamens usually 5, free, or more or less united ; carpels 2-5 ; ovules many ; endo- sperm fleshy. Campanula, Lobelia. (Pf. 4 5 :40.) Family 284. Goodeniaceae. Mostly Australian herbs and shrubs, with alternate (or opposite) leaves; flowers usually irregular; stamens 5, free, or cohering above; ovary 2-4- celled; ovules many; endosperm fleshy. Goodenia, Scaevola, Brunonia. ( Pf . 4 r> : 70. ) Family 285. Stylidiaceae. Mostly Australian herbs, with tufted, radical, or scattered and sometimes crowded stem- leaves; flowers usually irregular; stamens 3-2, mostly con- nate with the style; ovary 2-celled, many-ovuled; endosperm fleshy. Stylidium, Levenhookia. (Pf. 4 5 :79.) Family 286. Calyceraceae. South American herbs, with alternate leaves; flowers regular or irregular in involucrate heads; stamens attached to the corolla-tube, anthers free; ovary 1-celled; stigma capitate; ovule 1, pendulous; endo- sperm fleshy. Boopis, Calycera. (Pf. 4 5 :84.) Order Asterales. Composites. Flowers actinomorphic or zygomorphic, collected into involucrate heads; calyx small, and often forming a "pappus" ; stamens 5, epipetalous, mostly with their anthers connate, dehiscing introrsely; carpels 2, united, inferior, with one style which is 2-branched above; ovule one, erect, anatropous; endosperm 0. An immense order (commonly regarded as a family) of about 14,324 species, which are usually distributed among fourteen tribes, all of which are here raised to families. In the following arrangement the Helianthaceae are regarded as the lowest, from which the two principal phyletic lines have arisen, cul- 1915] BESSEY PHYLOGENETIC TAXONOMY 163 urinating on the one hand in the Eupatoriaceae, and on the other in the Lactucaceae. (Pf. 4 5 : 87.) Family 287. Helianthaceae. Sunflowers. Calyx not capil- lary ; receptacle chaffy ; usually with ray flowers ; mostly large and coarse plants, with leaves usually opposite. Helianthus, Zinnia, Rudbechia, Silphium. (Species 1364.) (Pf. 4 5 : 210.) Family 288. Ambrosiaceae. Eagweeds. Calyx not capil- lary ; receptacle chaffy ; without ray flowers ; mostly large and coarse plants, with leaves usually alternate, flowers diclinous. Ambrosia, Xanthium. (Species 74.) (Pf. 4 5 :220.) Family 289. Heleniaceae. False sunflowers. Calyx not capillary; receptacle usually naked; with or without rays; anthers tailless ; medium-sized plants with opposite and alter- nate leaves. Helenium, Gaillardia. (Species 449.) (Pf. 4 5 :251.) Family 290. Arctotidaceae. Gazanias. Calyx not capil- lary ; receptacle naked ; anthers tailless. South African plants with mostly alternate leaves. Gazania, Arctotis. (Species 278.) (Pf. 4 5 :307.) Family 291. Calendulaceae. Marigolds. Calyx not capil- lary; receptacle naked; anthers tailed. Old World plants, mostly tropical, with alternate leaves. Calendula. (Species 125.) (Pf. 4 5 :303.) Family 292. Inulaceae. Everlastings. Calyx from bracteose to capillary ; receptacle usually naked ; anthers tailed ; usually rayless; mostly low plants, with alternate leaves. Inula, Antennaria, Gnaphalium, Helichrysum. (Species 1580.) (Pf. 4 5 :172.) Family 293. Asteraceae. Asters. Calyx from bracteose to capillary; receptacle naked; usually with rays. Medium- sized plants, with alternate leaves. Aster, Solidago, Erigeron, Bellis. (Species 1815.) (Pf. 4 5 : 142.) Family 294. Vernoniaceae. Ironweeds. Calyx from brac- teose to capillary; receptacle naked; without rays; style branches hispidulous. Medium-sized plants, with mostly alter- nate leaves. Vernonia. (Species 788.) (Pf. 4 5 :120.) [Vol. 2, 1915] 164 ANNALS OF THE MISSOURI BOTANICAL GARDEN Family 295. Eupatoriaceae. Blazing-stars. Calyx from bracteose to capillary; receptacle naked; without rays; style branches papillose. Medium-sized plants, with opposite and alternate leaves. Lacinaria, Eupatorium. (Species 944.) (Pf. 4 5 :131.) Family 296. Anthemidaceae. Camomiles. Calyx a short crown or wanting; involucral bracts with scarious margins; receptacle chaffy or naked; usually with white ray flowers. Medium-sized plants, with alternate leaves. Anthemis, Chrysanthemum, Artemisia. (Species 915.) (Pf. 4"': 207.) Family 297. Senecionidaceae. Groundsels. Calyx capil- lary; involucral bracts mostly 1-seriate; receptacle naked; flowers mostly yellow, with or without rays. Medium-sized to large plants, with alternate leaves. Senecio, Arnica. (Species 1982.) (Pf. 4 5 :283.) Family 298. Carduaceae. Thistles. Calyx mostly capillary; involucral bracts multiseriate ; anthers tailed; receptacle usually bristly (not chaffy) ; without rays. Mostly stout plants, with alternate leaves. Carduus, Arctium, Cnicus. ( Species 1563. ) (Pf. 4 5 :312.) Family 299. Mutisiaceae. Mutisias. Calyx mostly capil- lary; receptacle usually naked; flowers all two-lipped. Medium to large (even woody) plants, of tropical or warm regions, with mostly alternate leaves. Mutisia, Chaptalia. (Species 550.) (Pf. 4 5 :333.) Family 300. Lactucaceae. Lettuces. Calyx mostly capil- lary ; receptacle usually naked ; flowers all strap-shaped. Small to medium-sized plants, mostly with a milky juice, and with alternate leaves. Lactuca, Hieracium, dehor him, Leontodon, (Taraxacum). (Species 1701.) (Pf. 4 5 :350.) THE BOTANICAL GAEDEN OF OAXACA C. CONZATTI Director of the Botanical Garden of Oaxaca, Mexico I. General At the end of the year 1909, when I was at the head of the Teachers ' Normal School of the State of Oaxaca, a post which I had held since the middle of 1891, I was asked by the Min- istry of Improvements, Colonization and Industry, at that time under Sr. Lie Don Olegario Molina, to assume the man- agement of the Botanical Garden which was to be established on the grounds of the Agricultural Experiment Station of the same state. This station is situated about four kilometers from the city and had been in operation for only a few months. Professor Don Felix Foex, the first director of the station, was entrusted with the establishment of the Garden. He had several interviews with me ; however attractive the proposition appeared to me, I could not decide to accept it. Finally, after much hesitation, I accepted the new position, and since then I have devoted myself to it entirely, even though success is doubtful ; without fear of being contradicted, I can say boldly that I have been everything in the Botanical Garden, laborer, manager, topographer, landscape gardener, clerk, gardener, excursionist, and a hundred other things besides. At the beginning of 1910 there was a general suspension for several months of the activities of the Station. As soon as the work could be resumed I devoted, with the half dozen men that I had at my command, the rest of that year and the whole of 1911 to the preliminary task of levelling, cleaning and adapt- ing, in general, the ground for the new branch of the Station. This was a mistake; I recognize it now when it is too late. I should have insisted that the Botanical Garden, which was to be established on the grounds of the Station, be absolutely independent of the latter, or else I should have refused its management. Unfortunately, I did neither, and to this date Ann. Mo. Bot. Gard., Vol. 2, 1915 (165) [Vol. 2 166 ANNALS OF THE MISSOURI BOTANICAL GARDEN I deplore the consequences of such a serious lack of fore- thought, since, depending on the wills of others with ideas differing from mine, the Garden will never be able to prosper, or will prosper with great difficulties on account of lack of freedom. Having finished the preliminary tasks which I had under- taken, I proceeded to make a sketch of the Garden as shown in fig. 1, which is here reproduced as approved by the authori- ties. As may be seen in the sketch, the Botanical (Jarden of Oaxaca is still in the process of formation. The tract of land assigned to it consists approximately of nine hectares, an area extensive enough to contain all the most prominent specimens of the mundane flora and all the characteristic specimens of the national flora. Of the three valleys of the Station to the east of the Oaxaca and Ejutla Railroad, the Garden occupies the middle one, which is the one best suited for that purpose and at the same time most accessible. At the beginning it was subdivided into five departments, somewhat unequal in size, together compris- ing a rectangle 400 meters in length (from north to south) by 200 meters in width (from east to west) ; but later this area was increased by an addition of 3,000 square meters, which was annexed to the southwest corner, and again by a sixth department, semilunar in outline, comprising 5,000 square meters, annexed at the middle part of the west side. Deduct- ing from this total area about two hectares which will be taken up by the prospective lake, walks, and lanes, there remain not more than seven hectares of land which can be utilized for the cultivation of plants. As I have shown in a recent work, the Botanical Garden of Oaxaca is the first and only one worthy of the name in the whole of the Republic. This fact alone, signifying a positive progress, should have been sufficient to enlist the support of the authorities, as well as the public in general; but contrary to what might be expected, its existence has been, especially recently, extremely neglected. I have made this clear in the opinion expressed in my reports to the higher authorities, as may be seen from the following : 1S151 CONZATTI BOTANICAL GARDEN OF OAXACA 167 Calz. ad A. P^mCTPAL. in s 3 o P 9 o o 3 'I am not at all satisfied with the progress of the Botanical Garden, especially during the second half of the fiscal year, 1913-1914. 168 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 means its existence has been extremely difficult, so much so that it would be practically impossible for it to continue under the same conditions for any length of time without failing for want of support. I must my m In the same report I point out : 'Such a difficult situation is due especially to the deplorable condi- tions which have depleted the Public Treasury, and that as soon as the present sad state of aifairs disappears (which, fortunately, seems to be already taking place), all the branches of the administration will again receive that encouragement of which they are in such great need.' And this I believe sincerely, since I have faith in the move- ment which is being started for the salvation of the country and for the restoration of peace. After all, this is the history of the development of every new idea; it is obliged to struggle on its own merits — with danger of being suppressed — against all kinds of difficulties. One of these, and certainly not the least which I have en- countered, has been the predominating instability everywhere, due to the political disturbances which have been ravaging the country for a long time. This circumstance and the abso- lute lack of means have prevented me from making the trips which I had planned in order to bring to the Garden some living plants, which to-day constitute the most pressing need of our institution. I am convinced that the life of the Botanical Garden depends essentially on providing it with plants. Since the departments are really well prepared, the essential thing now is to fill them with plants, preferably with the greatest possible number of specimens of the Mexican flora which are found in the mountains; and the only effec- tive way of obtaining them is to go and get them. As long as this cannot be done, the work of the Garden must be limited to the routine work of preserving what is already there. II. Detailed Description At the end of 1913, according to the compilation made at that time, the Botanical Garden contained the following 1315] CONZATTI BOTANICAL GARDEN OF OAXACA 169 * plants : 1,099 in the systematic department, 101 in the arbo- retum, 1,158 in the propagation department, and 1,035 in the geographical department and the fruticetum, or a total of 3,393 specimens. For reasons already mentioned, the Botan- ical Garden from then until now has not only remained stationary, since it has received no appreciable additions, but it has also deteriorated a great deal, partly because a great number of plants have dried up from lack of water, and partly because its personnel — reduced to only four workmen is insufficient to attend to the varied duties which are required. In fig. 1 some of the plants are indicated by black dots as occurring in the outer departments, arboretum and fruticetum, neither of which have any particular shape. GEOGRAPHICAL DEPARTMENT This department, on the contrary, is meant to represent in its main outlines the political map of the State of Oaxaca, the divisions of which are marked with the initial letters of the districts which constitute it. These districts at present are grouped, primarily on the basis of their climatic conditions, into six natural regions, as follows : Central, Cuicateca, Ser- rana, Istmica, Costena, and Mixteca, separated from one another by lanes two meters in width. The edges of these regions have already begun to receive — as a kind of an en- closure — the typical plants of each region, while the interior of each will receive the most characteristic vegetable produc- tions of the exuberant soil (see fig. 2). In accordance with this plan, the central region (fig. 2), which consists of the districts (see fig. 1) E — to the right of 0— (Etla), Zi (Zimatlan), M (Miahuatlan), E— to the left of C— (Ejutla), Tla (Tlacolula), and (Ocotlan), all border- ing on, or similar by their products to, district C (Center), shows now on its perimeter 121 specimens of Ceanothus azureus, a vigorous and elegant shrub of the hills which sur- round the Capitol. The point corresponding to Santa Maria del Tule, a small village in the same region and situated about two leagues east of Oaxaca, is planted with a shrub "Sabino del Tule" [Vol. ■■ 170 ANNALS OF THE MISSOURI BOTANICAL GARDEN (Taxodium distichum) two meters in height and a direct off- spring — by seed — from its historic parent. Among other things, it has the merit of being the oldest member of the department. The Cuicateca region, consisting of the districts Cui (Cui- catlan), Teo (Teotitlan), and Tu (Tuxtepec), is limited now to 65 specimens of Vallesia glabra, or "Tree of the Pearls," native of the Canyon of Tomellin. This small collection is characterized by its exuberant growth and uniform size. Of the districts which constitute this region, only Cuicatlan has received a supply of plants — twenty- two different specimens from Quiotepec. Among these are six plants of Bur sera sucedanea from Linaloe, called "Palo Hediondo" (fetid stick) by the natives of that place. Three districts form the Serrana region, Ix (Ixtlan), V. A. (Villa Alta), and Ch (Choapain) ; only very recently I have planted around these, 81 specimens of Cerocarpus fothor- gylloides, a beautiful rustic little tree which is native of this region. The perimeter of the Istmica region, composed of the dis- tricts J (Juchitan) and Te (Tehuantepec), was also planted in a similar manner with some ,54 specimens of an arboreal Pereskia, new to science, from the coast of Salina Cruz. In the district of Tehuantepec I have planted 30 plants coming from the same region and belonging to about a dozen species in several genera — Stemmadenia, P edilanthus , Mimosa, etc., and in the district of Juchitan species of several genera of the Cactaceae — Opuntia, Cereus, Mamillaria, Selenicereus, Echinocactus, etc. — have been planted. On the southern side of this department there are planted 40 palm-trees, species of Phoenix, about two meters high, bordering a walk which bears the name of the famous Bra- zilian botanist, Barbosa Rodriguos; while on the north side runs another walk, five feet wide, called "Andres Cesalpmo," along the edges of which we have planted 148 specimens of Poinciana Conzattii Rose, brought from Tehuantepec. Finally I shall mention the collection of Mexican agaves 1915] CONZATTI — BOTANICAL GARDEN OF OAXACA 171 3 P p p o o P P - o P P p p rD P O P p p f c 5 PI c 3 •I 4 i 5 p 5 r hich are in the district H (Huajuapam) of the Mixteca 3gion, as well as the fact that it is planned to introduce into [Vol. 2 172 ANNALS OF THE MISSOURI BOTANICAL GARDEN this department various groups of practically useful plants — industrial, tinctorial, poisonous, medicinal, etc. DEPARTMENT OF PROPAGATION This department is situated in the middle eastern part of the Botanical Garden and comprises an area of not more than half a hectare. Its shape is that of a semicircle bounded on its convex side by the Adolf Engler walk; this is the name of the famous author of the classification adopted by the Garden, with few very slight exceptions suggested by the 'Lexicon Generum Phanerogamarum ' of von Post and 0. Kuntze. The sides of this walk are planted for the time being with various specimens of Melia Azedarach, but in the near future these will be replaced by specimens of "Rosa-Cacao," an imposing pyramid-like tree with horizontal and vertical brandies. As indicated by the name, this department is devoted to the propagation of plants for this Garden and similar establishments in this and other countries. WALKS AND IRRIGATION CENTERS Of the walks of the Garden, the one called "Carlos Linneo" forms the western boundary line of the Garden and serves it, so to speak, as a base. It is a straight line 420 meters long, running from north to south, parallel to the Oaxaca and Ejutla Railroad, and throughout its length there are, five feet apart, 84 specimens of Casuarina stricta about three meters in height. Two other walks worth mentioning on account of their width (10 meters) are the Asa Gray and the John Lindley walks ; these run along the outer side of the systematic department and have as a border 105 laurels from India, as yet rather small. One of the far-reaching improvements for the progress of the Botanical Garden has been the establishment of a prac- tical irrigation system, which was first introduced at the end of 1913 and developed later as shown in fig. 2. For this purpose we first laid under the ground 400 meters of 2^-inch pipe through the center of the Garden from the large circular tank, situated on the southern slope, to the wide 1915] CONZATTI BOTANICAL GARDEN OF OAXACA 173 leading from the Station building on the north. This t> was the main artery and at fixed points, which were carefully selected beforehand, crosses were placed to mark the respec- tive connections. These consisted of lateral ramifications of smaller pipe which were to carry the water to the 35 irriga- tion centers, 50 meters apart, into which the Garden is sub- divided. All these centers must have nozzles, and at present there are 18 of them in working order; these are marked with crosses in fig. 2. To install them we have used 500 meters of smaller piping, so that a similar amount, if not a little more, would be required to complete the network. Of these irrigation centers eight belong to the arboretum, twelve to the systematic department, seven to the geographical depart- ment, five to the fruticetum, and three to the propagation department. As soon as the Botanical Garden has completed its irrigation system and has a sufficient supply of water for all seasons, we shall be able to consider its existence as assured. SYSTEMATIC DEPARTMENT Together with the two preceding departments, the geo- graphical and propagation departments, the systematic de- partment constitutes the central part of the Garden, and from the botanical point of view is the most interesting of them all. Many plants have already been planted in it, as may be seen in pi. 3, which represents the central part of the department ; but the empty places are still numerous, and the need of having them planted is great. The shape of this department is that of an immense cup, 200 meters long and measuring 145 meters at its widest part. As I have shown in a previous paper, which was published some time ago in the 'Memorias y Kevista de la Sociedad Cientifica " Antonio Alzate," ' of Mexico, and to which I now refer for a better presentation of this subject, 'its interior is subdivided into 45 large squares approximately equal, among which are distributed the 277 phanerogamic families of the " Syllabus" of Dr. Engler.' The plants in this department, therefore, are arranged strictly in the order of affinity, 174 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2, 1915] namely, vascular cryptogams and monocotyledons at the base, followed in order by the dicotyledonous groups, Apetalae, Polypetalae, and finally the Gamopetalae. With the latter the lineal series is closed, since according to the consensus of modern opinion they constitute the most highly differentiated group of flowering plants. In the preceding lines I have endeavored to condense the most prominent features relative to the life of the Botanical Garden of Oaxaca. They are totally without pretense on my part, although they would wish to carry to the minds of all those who may read them the same high concept which I myself have formed of such a progressive institution. In spite of the discouragement that I often feel about the Garden, I have confidence in its final success. Everything indicates that to-day the Republic is approaching rapidly a better era, which will be effected through organic peace and progress in its truest sense, since the horizon appears already free from the dark clouds. In concluding, I wish to say that the Botanical Garden of Oaxaca, after showing itself in the preceding lines in all its smallness, has the honor of sending its older brother, the Missouri Botanical Garden of St. Louis, its most cordial con- gratulations for the Twenty-fifth Anniversary, wishing it long life and abundant prosperity Explanation of Plate plate ;$ General view of the Botanical Garden of Oaxaca, Mexico, particularly of its Systematic Department. Ann. Mo. Bot. Gard., Vol. 2, 191 5 Plate 3 o > c d o > OCKAYN'E, BOSTON THE ORIGIN OF MONOCOTYLEDONY II. Monocotyledony in Grasses J. M. COULTER The University of Chicago Recently Dr. Land and I published 1 the results of an in- vestigation suggested by a specimen of Agapanthus umbel- latus, one of the South African Liliaceae, possessing two good cotyledons. It seemed to us that if the seedlings of the same species are indifferently monocotyledonous or dicotyledonous, there must be some evident relationship between the two con- ditions. These two conditions of the seedling of Agapanthus were compared critically, and Sagittaria was included in the investigation because it has stood, along with Alisma, for the typical monocotyledonous embryogeny, in which the terminal cell of a filamentous proembryo is said to give rise to the single cotyledon, in contrast with the dicotyledonous embry- ogeny, in which the corresponding terminal cell produces the stem tip, and the cotyledons are distinctly lateral. No con- trast would seem sharper and less capable of being confused with intergrades. The result of the investigation, as recorded in the paper referred to, was to show us that there are no such rigid cate- gories for cotyledony; that the cotyledonary apparatus is al- ways the same structure, arising in the same way, and vary- ing only in the details of its final expression. Briefly stated, the situation is as follows : In the embryogeny of both mono- cotyledons and dicotyledons, a peripheral cotyledonary zone gives rise to two or more growing points, or primordia ; this is followed by zonal development, resulting in a cotyledonary ring or sheath of varying length. If both growing points con- 1 Coulter, John M., and Land, W. J. G. The origin of monocotyledony. Bot. Gaz. 57:509-519. pi. 28-29. 1914. Ann. Mo. Bot. Gard., Vol. 2, 1915 (175) 176 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 tinue to develop equally, the dicotyledonous condition is at- tained ; if one of the growing points ceases to develop, the con- tinued growth of the whole cotyledonary zone is associated with that of the other growing point, and the monocotyledon- ous condition is attained. In like manner, polycotylcdony is simply the appearance and continued development of more than two growing points on the cotyledonary ring. It fol- lows that cotyledons are always lateral structures, arising from the peripheral zone developed at the top of a more or less massive proembryo. This reduces cotyledony in general to a common basis in origin, the number of cotyledons being a secondary feature. The constancy in the number of coty- ledons in a great group is no more to be wondered at than the same constancy in the number of petals developed by the petaliferous zone. This is a brief statement of the thesis of our previous paper, detached from the evidence upon which it was based. It was our purpose to extend the investigation far enough to include all of the representative regions of monocotyledons, so that the conclusion could be tested sufficiently to lead either to its abandonment or to its establishment. This second paper deals with a study of the embryos of grasses, which have been examined more extensively, perhaps, than the embryos of any other monocotyledonous group. As a result of this extensive study there are available many accurate records in the form of good figures, giving the details of embryogeny in such a way that interpretation is almost as satisfactory as it would be from the actual material. Of course this use of illustra- tions has been checked by the direct inspection of more or less material. The embryo of grasses early attracted special attention be- cause it does not seem to conform to the plan of the ordinary monocotyledonous embryo. Certain structures appear that could not be accounted for, but they enriched terminology. As a consequence, the nature of scutellum, epiblast, and coleoptile became subjects of discussion. It was to be expected that 1315] COULTER — ORIGIN OF MONOCOTYLEDONY 177 the embryo of grasses, with all of its unusual structures would be interpreted in terms of a rigid conception of the monocotyled embry in other words that the conventional monocotyledonous em- bryo would be read into the grass embryo. There is no better illustration of the com- pelling power of a preconception than this treatment of the grass embryos, for it so happens that they show all the intermedi- ate stages between dicotyledony and mono- cotyledony. Very early in the history of this subject, the scutellum came to be recognized a 5 tyled The corollary this propositi however c— was that it must be recog- nized also as a terminal structure. Any one who has seen the vascular system of the embryo of corn (fig. 1), the most highly specialized of all grass embryos, with its distinct axial cylinder, made up of stem cylinder and hypocotyl cylinder, and the er— tyle d strands lead off from the intermediate tyled plat just as do the strands of anv lateral tyled will understand Fig. 2. Embryo of Zizania aquat- ica : s, scutellum ; e, epiblast; c, cole- optile; X 11. After Bruns. the great difficulties in the way of interpreting this cotyledon as a terminal structure. The structure which pre- Fig. 1. Embryo of Zea Mays: s, scutellum; c, cole- optile ; the vascu- lar cylinder of the embryo is shown, made up of stem cylinder and hypo- cotyl cylinder, also the lateral origin of the cotyledon (scutellum) from the cotyledonary vascular plate; op- posite the vascular connection o f the cotyledon there ap- pears a group of procambium cells, marking the origin of another cotyle- donary strand con- nected with the suppressed second cotyledon (epi- blast) ; X18. sented the greatest difficulty, however, was the epiblast, usually defined as a small scale "opposite" or "over against" the 178 [Vol. 2 ANNALS OF THE MISSOURI BOTANICAL GARDEN cotyledon. The definition is accurate, for the epiblast occupies exactly the place of a second cotyledon opposite the large and functional one (fig. 2). If some one had found an epiblast vigorous enough to establish < < Fig. 3. Embryo of Leersia clandes- tine!,: s, scutellum; e, epiblast; c, cole- optile; X 44. — After Bruns. vascular connections, this debated structure would long since have been accepted as a second cotyledon, for the definition of it al- ways emphasized the fact that it is a scale in the right position for a cotyledon, but with no vascular strands." So obvious is the interpretation of the grass embryo when an epiblast is developed that Porteau in 1808, Mirbel in 1809, Turpin in 1819, and Bischoff in 1834, all called the epiblast a rudimentary cotyledon. The sub- mergence of this idea seems to have been due to Schleiden, who in 1837 dissented from this view, and it disappeared from literature. It reappeared in 1897, when Van Tieghem, in -s his paper on the embryo of grasses and sedges, 1 reiterated based chiefly upon the study of vascular connections. Any series of sections, cross or longitudinal, through the em- bryos of grasses, shows the fol- lowing facts : the so-called scutel- lum or functional cotyledon arising from the peripheral coty- ledonary ring or sheath which surrounds the apex of the em- bryo, and establishing vascular connections laterally with the cotyledonary plate; the epiblast in a similar relation to the coty- Fig. 4. Embryo of Oryza sativa: s, scutellum; e, epiblast; c, cole- optile; X 22 .—After Bruns. ledonary ring on the opposite side, and varying in develop- ment from a structure somewhat smaller than the large cotyledon, to complete suppression; and the apex of the 1 Van Tieghem, Ph. Morphologie de l'embryon et de la plantule chez les Graminees et les Cyperacees. Ann. d. Sci. Nat., Bot. VTII. 3:259-309. pi. 1^-16. 1 Oc7 | • 1915] COULTER ORIGIN OF MONOCOTYLEDONY 179 $- — o- e- embryo, continuing beyond the cotyledonary ring or sheath, and producing a variable number of leaves. The early appearance and rapid develop- ment of these leaves seems to account for the abortion of one of the growing points. I am convinced that if grass embryos had been the only monocotyledonous embryos studied, we should never have heard of terminal cotyledons. Some common grasses, whose embryos have been figured by Bruns, 1 may be used to illustrate stages in the abortion of the second cotyledon. The abortion always is accompanied by the diver- sion of the growth of the whole cotyledonary zone in connection with the growing point that remains active; so that growing tissue is not suppressed, but develops as one structure rather than as two. In Zizania aquatica (fig. 2), the so-called epiblast is very conspicuous, arising Fig. 5. Embryo of 8 par Una cyno- suroides: s, scutel- lum; e, epiblast; c, coleoptile; X 13. — After Bruns. Fig. 6. Embryo of Leptochloa arab- ica : s, scutellum ; e, epiblast; o, cole- optile; X 44. — After Bruns. as distinctly from the per- ipheral cotyledonary ring as does the so- called scutellum, and attaining at least one- quarter to one-third of its length. This unusual development of the second cotyledon is associated with the fact that the stem axis above the cotyledons develops a long internode, so that the first leaves begin to appear at an unusual distance from the origin of the cotyledons. In fact, in this case the length of the second cotyledon is approximately the length of the first inter- node, and where the leaves begin this coty- ledon ends. In Leersia clandestine/, (fig. 3), the second cotyledon (epi- blast) approaches the large cotyledon in length even more 1 Bruns, Erich, Der Grasembryo. Flora 76: 1-33. pi. 1-2. 1892. Fig. 7. Embryo of Triticum vulgare: s, scutellum ; e, epi- blast ; c, coleoptile ; X 22.— After Bruns. I VOL. 2 180 ANNALS OF THE MISSOURI BOTANICAL GARDEN S— - than does that of Zizania, and all the connections of the various organs show a lateral origin for the cotyledons, and a terminal origin for the ' ' coleoptile, ' ' a structure made up chiefly of leaves arising from an indistinctly differen- tiated stem-tip region. Oryza sativa (fig. 4) is interesting in the relation of the parts of the embryo, the ' ' scutellum ' ' and ' ' epiblast ' ' being opposite and well-balanced structures, between which the prominent plumule (a name ex- pressing the real char- acter of the 1 * coleop- tile") is evident. j Transverse section In bpttT- tina cyno- sur oid e s 5), the Fig. 8. through cotyledon (s), show- ing it embracing the plumule (c) of Zea Mays: the plum- ule shows three distinct leaves and the terminal stem tip; the succession of oppo- site vascular bundles indi- cates that a bundle opposite that of the cotyledon is miss- ing, but its rudiment is evi- dent in a lower section; X20. g- small cc ledon ( epi- blast) is less p r o m i - nent. but its a — v — relation to the functioning cotyle- don, and the relation of both to the plumule are evident. In Leptochloa arabica (fig. 6) and in Triticum vulgar e (fig. 7), the epi- blast remains very small, but the significant connections are evident. It is in the embryo of Zea Mays that this reduction series reaches its extreme expression in the complete disappearance of the epiblast or second cotyledon (fig. 1), whose position is indicated merely by more or less protuberant Fig. 9. Transverse section through the cotyledonary plate of Zea Mays: the functioning cotyledon (s) does not overlap a small protuberance, which represents the site of the miss- ing cotyledon (epiblast), as in- dicated also by the appearance of a procambium mass (a), which is the rudiment of a former vascular connection ; X20. 1915] COULTER — ORIGIN OF MONOCOTYLEDONY 181 tissue and by the very obvious vascular relations. A cross- section of this very specialized embryo is instructive (figs. 8 and 9). The large functional cotyledon is seen originating on one side, embracing the vascular axis of the embryo and more or less overlapping the other side, where in most grasses the second cotyledon (epiblast) appears. Moreover, in the section of the centrally placed plumule, with its succession of leaves, a section of the stem tip may be seen, clearly representing the axis of the embryo, with no suggestion of a lateral origin. A transverse section through the cotyledonary plate (fig. shows some tissue developed at the site of the missing cotyle- don (not overlapped by the functioning cotyledon). This is emphasized by the appearance of a mass of procambium at the base of the protuberance, which in other grasses develops into the epiblast. This procambium is distinctly a rudiment of a former vascular connection. Some idea of the frequency with which the second cotyledon appears among the grasses may be obtained from the excel- lent work of Bruns on the grass embryo, published in 1882, and from the work of Van Tieghem, already cited, published in 1897. Bruns examined 82 genera, representing 12 tribes. In 29 of these genera epiblasts were present, and the genera represented 9 of the 12 tribes. The tribes in which no epiblasts were found were Oryzeae, Agrostideae, and Aveneae. The situation in the Agrostideae is noteworthy, for 13 genera were examined, and no trace of an epiblast found. Festuceae may be mentioned, for 20 of its genera were examined, and only 4 of them were found to possess epiblasts. Taking Bruns' re- sults as a whole, they indicate that approximately 40 per cent of the grasses still develop a second cotyledon to a stage that enables it to be recognized under ordinary inspection as a definite structure. The work of Van Tieghem included a somewhat wider range of forms, 91 genera being examined, and 61 of these showed epiblasts. This suggests that perhaps in as many as two- thirds of the grasses a second cotyledon is more or less ob- vious. In any event, it is certain that the grasses as a whole exhibit a remarkable number of transition stages from dicoty- I Vol. 2 182 ANNALS OF THE MISSOURI BOTANICAL GARDEN ledony to monocotyledony ; and this fact strongly supports the view that grasses are a comparatively primitive assem- blage of monocotyledons. It is not difficult to explain the prolonged misconception concerning monocotyledony. When the first detailed studies of monocotyledonous embryogeny were made by Hanstein, and supplemented by Famintzin, a form (Alisma) with a fila- mentous proembryo was selected. If a form with a massive proembryo had been selected for these early investigations, there would probably have been no misconception, for in such proembryos the peripheral (that is, lateral) cotyledonary zone is so evident that it could hardly have escaped recognition. Since that time, embryogeny that starts with a filamentous proembryo has been regarded as the typical embryogeny, and all other kinds of proembryos have been dismissed as excep- tions. In the case of this filamentous proembryo, it was ob- served that the terminal cell passed into the quadrant and octant stages, and later a terminal cotyledon appeared. It seemed safe to conclude that the terminal cell had developed the terminal cotyledon. The inference was true so far as it went, but it failed to recognize the fact that the terminal cell develops other structures as well. With the origin of the terminal cotyledon disposed of, the conclusion was confirmed by the appearance at its base of a notch, from which arose the stem tip. What could be more obvious than that the stem tip is lateral in origin, and therefore must arise from the cell of the proembryo behind the terminal one? In this way the conventional embryogeny of monocotyledons was established, and the relation of monocotyledony to dicotyledony became completely obscured. The facts not observed in these earlier investigations are as follows : The terminal cell of the proembryo forms a group of cells; the peripheral cells of this group develop the cotyle- donary ring or sheath, on which two growing points appear. One of these growing points soon ceases to be active, and the whole zone develops in connection with the other growing point; but at the base of the growing cotyledon a notch is left by the checking of the other growing point. This notch 1915] COULTER — ORIGIN OF MONOCOTYLEDONY 183 is really the space between the two very unequal cotyledons, which surround the real apex of the embryo. The apex of the embryo is at the bottom of the notch, and not at the tip of the large embryo. This apex soon begins to form leaves, and the so-called stem tip appears issuing from the bottom of the notch, in a relation apparently lateral only because the two cotyledons are so unequal. Furthermore, when the stem tip is examined, it is found not to be a stem tip, but a cluster of leaves whose rapid development has aborted one of the grow- ing points on the cotyledonary zone. All this is very obvious in grasses, and is equally obvious in any massive proembryo, but it escaped the earlier observers of filamentous proembryos. The general conclusion is that monocotyledony is simply one expression of a process common to all cotyledony, gradually derived from dicotyledony, and involving no abrupt transfer of a lateral structure to a terminal origin. This paper was prepared in collaboration with Dr. W. J. G-. Land, who also supplied the material and made the illus- trations. THE HISTORY AND FUNCTIONS OF BOTANIC GARDENS ARTHUR W. HILL, M.A., F.L.S. Assistant Director, Royal Botanio Gardens, Kew There are three things which have stimulated men through- out the ages to travel far and wide over the surface of the globe, and these are gold, spices and drugs. It is to the two latter of these universal needs of man that we may trace the origin and foundation of botanic gardens. The value of spices has led to the foundation of more than one botanic garden in the tropics, while to the necessity for drugs must be attributed the formation of the earliest botanic gardens in Europe. Before entering more fully into the history of the found- ing of the various botanic gardens it may be pointed out that progress in the science of botany and the establishment of gardens were by no means contemporaneous. To the Greeks, for instance, we owe the foundation of our knowledge of the classification of plants, and these early botanists were assidu- ous in collecting plants from all available sources and in drawing up accurate descriptions. Little interest, however, would appear to have been aroused in them to cultivate the plants they so carefully de- scribed, and the only record we have of the existence of any- thing of the nature of a botanic garden is the mention of Aristotle's Garden at Athens which he bequeathed to Theo- phrastus, by whom it was newly equipped and improved. Prior to the interest displayed by the Greeks in the vegeta- tion of the earth and quite independent of their influence we find evidence of the formation of gardens in Egypt, Assyria, China, and subsequently in Mexico — gardens not strictly botanic in our more modern sense but enclosures 1 set apart 1 See Greene, E. L. Landmarks of botanical history. Smithsonian Misc. Coll. 54 x :pp. 56-57. 1909. No doubt Theophrastus (370-286 or 262 B. C.) gained his intimate knowledge of plants very largely from the specimens cultivated in this early Athenian garden. Ann. Mo. Bot. Gard., "Vol. 2, 1915 (185) [Vol. 2 186 ANNALS OF THE MISSOURI BOTANICAL GARDEN for the cultivation of plants of some definite economic or aesthetic value. In considering the history of this subject we look back to the earliest history of mankind, with which gardening in some form is inseparably connected, for, as Francis Bacon reminds us: "God Almightie first planted a Garden and indeed it is the Purest of Humane Pleasures. It is the greatest refreshment to the spirits of man; without which Buildings and Palaces arc but grosse Handyworkes: and a man shall ever see that when ages grow to civility and elegancie men come to Build stalely sooner than to garden finely as if gardening wvre the greater Perfection." We are still exercised to seek out and grow "every tree that is pleasant to the sight and good for food," and the "tree of life" also in the midst of the garden is ever the object of our inquiries. It would be well indeed if at this present time we could discover that tree whose leaves were to be "for the healing of the Nations." The earliest garden of which we have any representation is the Eoyal Garden of Thotmes in of about the year 1000 B. C, which was planned by Nekht, head gardener of the gardens attached to the Temple of Karnak. 1 This Royal Garden, rectangular in outline, with its rows of date and branched doum palms and with its vine pergola and lotus tanks, was probably in the nature of a pleasure garden, while those at- tached to the temples may well have been of more economic importance. The Chinese, 2 however, should, as might be supposed, be credited with being the real founders of the idea of botanic gardens, since it is clear that collectors were de- spatched to distant parts and the plants brought back were cultivated for their economic or medicinal value. The semi- mythical Emperor Shen Nung, of the twenty-eighth century B. C, is considered to be the Father of Medicine and Hus- bandry and is said to have tested the medical qualities of herbs and discovered medicines to cure diseases. If this be 1 See Holmes, E. M. Horticulture in relation to medicine. Roy. Hort. Soc, Jour. 31: pp. 44-45. /. 11. 1906. 8 Bretschneider, E. Botanicon sinicum. China Branch Roy. Asiatic Soc, Jour. N. S. 25: p. 24. 1893. I 1915] HILL BOTANIC GARDENS 187 correct, it was but a repetition of history which led to the foundation of the monastic herb gardens in the ninth century A. D., and the subsequent institution of botanic or herb gar- dens in connection with the medical faculties of the earliest European universities. We learn from Bretschneider also that the Han Emperor Wu Ti (140-86 B. C.) planted a number of rare herbaceous plants and trees brought from the southern regions in the garden of his palace and the following plants have been identified from the list enumerated: Nephelium Litchi, N. logan, Areca Catechu, the banana, Quisqualis indica, Cana- rium album, C. Pimela, Cinnamomum Cassia, Canna indica, and sweet oranges. He also despatched officers to the north- western frontiers of China, who brought back reports on the productions of this region. Ancient Chinese authors ascribe to Wu Ti the introduction of the vine, pomegranate, saff- flower, common bean, cucumber, lucerne, coriander, walnut, etc. It is a fact of no small interest in this connection to remem- ber that the modern world has turned to China and that her vast botanical treasures have only recently been seriously explored through the enterprise of British, French, and American botanists for the enrichment of our botanic gar- dens and pleasure grounds. The establishment of gardens in Mexico is a noteworthy fact— though we have but little information about them n must have been autochthonous and inde- pendent of such institutions in the Old World. Prescott 1 tells us, and we have reason to believe his account to be true, that Montezuma had extensive gardens filled with fragrant shrubs and flowers and especially with medicinal plants. New Spain, indeed, furnished more important species of medicinal plants perhaps than any other part of the world, and their virtues were understood by the Aztecs, who are credited with having studied medical botany as a science. The gardens at Iztapalan 2 and Chalco 3 are said to have been stocked with 1 Prescott, W. H. Conquest of Mexico 2: pp. 110, 111. 1847. [3rd ed. London.] 8 2 8 Ibid. pp. 60 and 61. Ibid. 3: p. 37. 1847; Clavigero, D. F. S. Stor. del Messico 2: p. 153. [Vol. 2 188 ANNALS OF THE MISSOURI BOTANICAL GARDEN trees and plants scientifically arranged, and the gardens at Chalco, which were preserved after the Conquest, furnished Hernandez with many of the specimens described in his book. 1 The cases cited, however, have little more than an academic interest for us and have in no way influenced the founda- tion of modern botanic gardens. These we can trace back to monastic institutions and probably to the famous injunc- tions of Charlemagne, 2 the direct outcome of which was the establishment, among others, in the ninth century, of the "hortus" at St. Gall with the attendant "herbularis," or Physic Garden, this latter being the precursor of the physic gardens established in connection with the medical faculties of the Italian and other universities in the sixteenth century. It is fortunate that we have preserved to us exact details of the "hortus" and " herbularis ' ' at St. Gall, with lists of the plants cultivated therein. 3 The hortus was an obloi containing eighteen rectangular beds, while the Physic Garden, or herbularis (see fig. 1), formed a square set with similar beds and having the doctor's house close at hand. The monks being bound to live on pulse, vegetables and fruits and to gather the same for themselves, the garden and its cultivation were of especial importance in the monastery. To the fostering care of the monks and to their knowledge of drugs, horticulture and botany, in common with other arts and sciences, we owe a debt the magnitude of which it is difficult to estimate. We do well to recall at this point the services rendered in recent years to the biological sciences by the labors of Gregor Mendel in the monastic garden at Brunn, if only to emphasize how widespread and far-reaching are the functions involved in the true idea of the botanic garden. The fourteenth and fifteenth centuries, as is well known, s times of a great revival and 1 Hernandez, F. Nova plantarnm aniiiialmm et mineralium Mexicanorum historia. Rome, 1651. 2 Holmes, E. M. Horticulture in relation to medicine. Roy. Hort. Soc. Jour. 31: p. 50. 1906. 8 Archaeological Inst., Jour. 5: P- 113; see also Amherst, A. History of gardening in England p. 6. 1896. [2nd ed.] 1915] HILL BOTANIC GARDENS 189 the science of botany received its due share of attention. Unfortunately, energy was chiefly employed in attempting to identify the plants named by the Greek writers with those of Western Europe and progress in the science was only fitful. The compilation of herbals was the main occupation Fig. 1. Monastery of St. Gall. Physic Garden: 1, Fasiolo; 2, Sat- aregia; 3, Rosas; 4, Sisimbria; 5, Cumino; 6, Lubestico; 7, Feniculum; 8, Costo; 9, Liliuni; 10, Salvia; 11, Ruta; 12, Gladiola; 13, Pulegium; 14, Fenugraeca; 15, Mentha; 16, Rosmarino. The Cemetery contained apples, pears, peaches, mulberries, plums, laurels, figs, hazelnuts, service, chestnuts, medlars, quinces, almonds, and walnuts. of industrious botanists and many of these works, though of little botanical value to-day, can be treasured by us as store- houses of artistic beauty. With the real growth in the knowledge of plants and their uses there grew up also a mass of superstitious information, [VOL. 2 190 ANNALS OF THE MISSOURI BOTANICAL GARDEN partly founded on old tradition, increased with the importa- tion of strange drugs, 1 and partly no doubt invented by the herbalists and drug-sellers to prevent any infringement of their monopoly in plants of real or supposed medicinal virtue, and to frighten the ignorant from attempting to collect the plants for themselves. The faint resemblance of the mandrake root to the human form, for instance, probably suggested its use as a remedy for sterility; it is still sold to-day in Egypt as a charm. Its use may have led to the discovery of its anaesthetic qualities since it was used in ancient times for this purpose, and the legends which abounded as to the danger of death to those who gathered the root may have been circulated in order to try to prevent its use for criminal purposes. It was largely owing to the need of protecting the doctor and apothecary against the drug-sellers that the growing of "simples" in recognized gardens had its origin. As the seats of the medical profession were established in the uni- versities and monasteries, these institutions set apart definite enclosures for the cultivation of medicinal herbs, the "sim- plicia" or "simples" from which the "remedia composita" were prepared by the apothecaries. Since the universities and monasteries were generally situated in towns, their physic gardens were usually small, and on the continent of Europe we still see these ancient gardens, which have been gradually transformed into the botanic gardens of the universities. In connection with the growth of learning and increase of observation which is noticeable in the arts and sciences at this time of renaissance, it is strange that biology was still so largely under the thrall of superstition and curious invention. Reference to the early herbals, such as the 'Bucli der Natur* (1475), the 'Herbal of Apuleius' (1484), and the 'Grant Her- bier' (1526), shows both as regards text and illustration a per- sistent state of ignorance of facts, which could easily have been remedied by observation, and possibly does not represent 1 Medicinal plants were imported from the Continent in a dry state, hence the English word "drug," which is part of the Anglo-Saxon verh "drigan," to dry. 1915] HILL BOTANIC GARDENS 191 the true state of the knowledge of the more competent medical botanists of the period. The herbal of Brunfels (1530), with its beautiful and accurate illustrations but indifferent text, and those of Bock, Fuchs, Cordus, and many others, may be taken as evidence of the rapid advance that was taking place in the knowledge of plants, though the fabulous and mythical still found adherents even amongst the most learned. Private physic gardens, as distinct from the monastic herb- aries, existed towards the end of the fifteenth century, and some of these developed into municipal gardens for the grow- ing of " simples." The botanic garden at Padua, which ap- pears to have been one of the earliest of these gardens, was founded in 1545 on the exact spot which it now occupies near the church of S. Antonio and S. Giustino. The garden owes its origin to the sound suggestion put forward at the end of the year 1542 by Francesco Bonafede, who in 1533 had founded the chair of "simples" (Lectura Simplicium) — the first in Europe — at the University of Padua. This garden is of especial interest, as not only have we an excellent account of it written by de Visiani, 1 but also because it is preserved very largely in its original condition. The cir- cular wall by which it is enclosed, though not the original one built in 1551, occupies the same site, and was rebuilt between 1700 and 1707; within the wall the garden is laid out in numerous little beds with stone edgings. The garden under- went many vicissitudes and fell into considerable decay, but in the year 1837 it was thoroughly restored, and the arrangement of the beds may well be a restoration of the original condition of the garden. In any case it affords an excellent example of the type of geometrical garden illus- trated in horticultural books published at the end of the sixteenth and beginning of the seventeenth centuries, 2 which for so long a time dominated garden design on the Continent. 1 de Visiani, It. Dell' origine ed anzianita dell' orto botanico di Padova. Padua, 1839. Saccardo, P. A. L'orto botanico di Padova nel 1895. pi. 1-8. f. 1. Padua, 1895. * See illustrations of the gardens of De Vries, 1580-1583, reproduced by Sir F. Crisp in 'Illustrations of some mediaeval gardens,' 1914; and cf. Mariani, Flori- legium renovatum et auctum. Frankfurt, 1641. [Vol. 2 192 ANNALS OF THE MISSOURI BOTANICAL GARDEN It is to be regretted that the principal features have been somewhat obscured by the growth of trees, but the ground plan fortunately remains unaltered. Pisa in 1544, Bologna in 1547, and others, 1 quickly followed the lead given by Padua. We are fortunate in possessing an elaborate plan of the Pisan garden published in Tilli's catalogue 2 of 1723 with a list of the plants cultivated in the various beds and enclosures, the latter being here reproduced. EXPLICATIO PROSPECTUS HORTI PISAN [ 1. Topiarium magnum instar Tentorii, Cupressinis Arboribus flexilibus, & ferreis catenis cireumdatum. 2. Umbraculum primum venustum, opere topiario, Citris Ar- boribus, ac Citroidibus poma suaveofentia fercntibus instruc- tum, & fontibus ornatum. 3. Umbraculum alteram Citroidibus Florentinis replotum. 4. Vaporarium pro Plantis Americanis. 5. Vaporarium gestatoriimi. 6. Locus pro Plantis Aeeyptiis aqiiarn lvspuentibus. 7. Vaporarium cum laminis vitreis fixum ad semina vegetanda. 8. Paries per totam longitudinem Aurantiorum Olyssipponen- sium, aliarumque: Arborum poma sustinens. 9. Fenestrae Ilypocausti. 10. Fenestrae Ilybernaculi. 11. Platea cum variis Aloes Plantis. 12. Nemus exoticarum, & indigenarum Arborum. 13. Hydrophylacia, seu Castella. 14. Locus pro Plantis montanis, & Sylvesiribus. 15. Laboratorii Chimici, in quo Anthlia Pneumatica reperitur, pars externa Ilortum respiciens. Supra vero extat infundi- bulum ad pluviam recipiendam, de qua fuse D. G. Derham in suis transactionibus, ac etiam in Demonstr. cap. iii. pag. 23. mentionem facit; eadein pars externa variis fontibus, ac lapidibus figuratis est ornata; ibi scilicet reperiuntur As- troites, qui in Metallotheca Mercati pag. 235. & Corallites, Placentae, Lapis Lumbricatus cap. 55. quorum etiam aliqui sunt Lapides Cerebri formes, an hue allati sint ex Sicilia, vel Sardinia, aut ex Jamaica, ut Rayus Hist. Tom. iii. pag. 5. ex Sloanis verbis, adhuc nescimus. 1 Botanic gardens were founded in Zurich, 1560; Bologna, 1568; Lryden, 1577; Leipzig, 1579; Montpellier, 1598; Paris, 1597, known as Jardin des Phintes after 1635; Heidelberg, before 1600; Giessen, 1605; Strasburg, 1620; Oxford, 1621; Jena, 1629; Upsala, 1657; Chelsea, 1673; Berlin, 1679; Edinburgh, 1680; Amster- dam, 1682. See also foot-note, p. 209. 2 Tilli, M. A. Catalogus plantarum Horti Pisani. Florence, 1723. Ifil5] HILL BOTANIC GARDENS 193 16. Pergulae Laurorum. 17. Prunorum diversae Arbores murum 18. Aurantiorum Arbores. >nes Plantarum secundum earum propriam naturam, areolis contentarum. 19. Locus Herbis tantuni Ilort 20. Locus Acanaceis Plantis. 21. Locus Plantis Umbelliferis. 22. Locus Plantis Palustribus. 23. Locus Plantis Venenatis. 24. Locus Plantis Odoratis. 25. Locus Plantis Bulbosis. 26. Florilegii locus. 27. Vaporarium fixum, ac fimo similes Plantae exoticae alu pleturn, ubi Ananas, & 28. Ostium primum. 29. Ostium Laboratorii Chimici, ubi Anthlia reperitur, aditum respiciens. 1 30. Ostium alterum Horti publici: intus insignium Botani- corum Virorum effigies visuntur. 31. In Tecto Infundibulum pluviam recipiens. 32. Paries Aurantiis Hermaphroditis ornata. 33. Platea. 34. Ubi Muscae odoratae D. Chimentelli oriuntur. 35. Aditus qui ad ostium Viae publicae ducit: ibi Balenae, & Physeteris ossa suspensa, ut pagina 4. hujus Catalogi, ubi de Agarico agitur. 36. Fenestrae Domus Custodis. 37. Fenestrae Musei In earum medio Inscriptio haec legitur. The beds at Pisa are arranged on the geometrical plan and the picture of the garden shows a perfect specimen of the typical formal garden of the end of the sixteenth century. The plants were grouped chiefly according to their properties and morphological characteristics : Thus one finds beds for poison- ous plants, prickly plants, smelling plants, bulbs and marsh plants. "Aloes" (Aloe, Gasteria, etc.) were also grown and are figured in the catalogue and there was a "vaporarium pro plantis Americanis. ' ' The lectures on " simples' ' delivered at the early Italian universities were not at first accompanied by demonstrations upon living specimens, but the growing of the plants in 1 This and the remaining buildings, etc., are shown on a separate plan which is not reproduced here. [Vol. 2 194 ANNALS OF THE MISSOURI BOTANICAL GARDEN definite gardens led to the establishment of demonstrations upon living specimens of the medicinal plants, and at Padua sixteen years after the foundation of the garden, a separation was made of the "Lectura" from the "Ostensio simplicium, ' ' or demonstration of living plants. Botany, however, in all these early universities to which gardens were attached was merely ancillary to medicine. At Montpellier, for instance, the same professor taught anatomy in winter and botany in summer, and as late as 1773 anatomy, surgery and botany formed the subjects for one and the same professor at Jena. Very soon after the founding of the gardens at Padua and Pisa, plants other than those of strictly medicinal value were introduced into the physic gardens. This was due to the revival of interest in the plant world which took place about the middle of the sixteenth century and to the desire for travelling and interest in collecting which then sprang up. Conrad Gesner, writing in 15(11 in the 'Horti Germaniae,' 1 mentions that in botanic gardens not only medicinal herbs were cultivated but also other plants, especially rare ones, for the purpose of observing and admiring nature: "Hortorum alii vulgares sunt, utilitatis tantum gratia confiti: in quibus olera, legumina, vites, fructus qui edendo sint, A: gramen, usum honiini aut pecori praebent. Alii medicinales, ut Medicorum & Pharmacopolaram : in quibus non hortenses tantum stirpes, sed etiam sylvestres omnis generis, & peregrinae quoquo coluntur, propter remedia quae ex ipsis earumve parti- bus homini fiunt. Alii similes istis, sed magis varii, in quibus non solium plantae remediis nobiles, sed aliae etiam quae uis rariores praesertim coluntur, propter admirationem & contcni- plationem naturae." John Ray visited both Padua and Pisa early in 1664; refer- ring to the garden at Padua, he says: "Here is a public Physick garden, well stored with simples but more noted for its prefects, men eminent for their skill in Botanies. " The Pisan garden at this time would not appear to have been in a very flourishing condition since Ray merely remarks, "The 1 Gesner, Conrad. Horti Germaniae p. 237 verso. Strasburg, 1561. 191; ] HILL BOTANIC GARDENS 195 Physick Garden at our being there but meanly stored with simples." 1 In particular, Gesner 2 alludes to several gardens at Padua and mentions the one under the charge of Anguillara, which was no doubt the Botanic Garden, as having a fine collection of plants with representatives from Syria, Crete and other dis- tant places. He refers in the first place to the Garden of Caspar a Gabrielis "vir inter nobiles Patavinos longe nobi- lissimus," and then to "Priulanus hortus magnificus," which was under Aloisius Anguillara (Romanus). Gesner 's account is as follows : "Ibidem Priulanus hortus magnificus, plantis variis & raris e Syria etiam accersitis admirationi est. Omnes vero omnium, ni fallor, hortorum magnificentia simul, & stirpium in eo vari- arum omnis generis, e Creta etiam & aliunde peregrinarum, numero laudes facile vincit publicus ille Patavii in medicorum gratiam inclyti Senatus Veneti liberalitate institutus hortus, cui hoc tempore Aloisius Anguillara Romanus, vir in stirpium historia nostro seculo exercitatissimus atque peritissimus omnium, magna cum laude praeest." According to Saccardo, 3 Luigi Squalermo (detto Anguil- lara) was the first prefect "dell 'orto padovano ed ostensori dei semplici" from 1546 to 1561. From this time onwards, no doubt, the tendency was to grow as many plants as possible, and a healthy rivalry commenced between the various botanical establishments as to who could show the greatest number of different species in cultivation. 1 Ray, J. Travels through the Low Countries 1: p. 182. 1738. [2nd ed.] Ray mentions the following eminent men at Padua: Aloysius Mundella, Aloysius Anguillara, Melchior Guilandinus, Jacobus Antonius Cortusus, Prosper Alpinus, Joannes Veslingius. Saccardo, loc. cit. p. 7, gives the following list of Prefects of the Paduan Garden : 1546-1561 Luigi Squalermo (detto Anguillara). 1561-1589 Melchiore Guilandino. 1590—1603 Giacom' Antonio Cortuso. 1603—1616 Prospero Alpini (o Alpino). 1616-1631 Giovanni Prevozio (Prevot). 1631 Giovanni Rhodio, iosto rinunciatario. 1631-1637 Alpino Alpini. 1638-1649 Giovanni Veslingio. 2 Gesner, C. De Hortis Italiae. Loc. cit. p. 239 verso. 8 Loc. cit. p. 7. [Vol. 2 196 ANNALS OF THE MISSOURI BOTANICAL GARDEN In the botanic garden at Paris, for example, in the year 1636, there were about 1,800 species under cultivation and the num- ber had risen in 1640 to 2,360, and in 1665 to as many as 4,000 species. With the interest aroused in the collection and cultivation of plants came also the interest in their description and illus- tration, and many bulky and costly works were produced to illustrate the plants grown in botanic gardens. In Great Britain the foundation of the botanic gardens at Oxford, Chelsea, and Edinburgh, was preceded by the estab- lishment of several interesting private gardens devoted to the cultivation of medicinal herbs and plants of botanical interest, catalogues of which were published. The Rev. Wil- liam Turner (1510-1568), who has been called the "Father of English Botany," had a garden somewhere at Kew and after- wards a renowned garden at Wells, when he was Dean of the Cathedral. Then there was the noted physic garden of John Gerard (1545-1612) in Holborn, at that time the most fashion- able district in London, the catalogue of which — published in 1 596 — enumerates 1,030 plants and is of interest as being the first complete catalogue ever published of the contents of a single garden. His 'Herball,' published in 1597, was not his own work, but was simply a translation by a certain Dr. Priest of the 'Stirpium Historiae Pemptades' of Dodoens, which Gerard adopted and published as his own. On the title page of the edition of 1597, a garden is figured which has been generally considered to represent Gerard's own garden in Holborn, but as Sir Frank Crisp 1 points out, he obviously bor- rowed his illustration from an engraving by A. Collaert, representing a garden of A. D. 1590, in April, much in the same unscrupulous manner as he borrowed his text. Among other early private physic gardens of interest in connection with the history of such institutions in England may be mentioned the garden of Thomas Johnson, M.D., the apothecary who had a garden on Snow Hill, in 1633 — he it 1 Guide for the use of visitors to Friar Park, Henley-on-Thames, Pt. II. Illustrations of some mediaeval gardens p. 87. 1914. The illustration reproduced by Gerard is to be found on the title page of Tabernaemontanus, J. T. Kreuterbucb. [eds. of 1664 and 1687.] 1915] HILL BOTANIC GARDENS 197 was who brought out the improved and enlarged edition of Gerard's 'Herball' in 1638. The garden of John Parkinson (1567-1650), apothecary to James I, and King's Herbalist in Long Acre, and that of John Tradescant (died 1638) the elder, at Lambeth, are also worthy of particular mention. John Tradescant, his father and his son were all of them botanists, collectors, and travellers. Tradescant the elder, who was gardener to various noblemen and also to Queen Elizabeth, was appointed Gardener to Charles I and founded a garden at Lambeth. This garden, after that of Gerard, was probably the most important early botanic or physic garden in England, and a catalogue of the plants therein was pub- lished in the 'Museum Tradescantianum ' by his son in 1656. In addition to the garden, the Museum is worthy of notice in passing, since the curiosities it contained were bequeathed by the younger Tradescant to Mr. Ashmole, and formed the nucleus of the collection in the Ashmolean Museum at Oxford. 1 Parkinson was created King's Herbarist, "Botanicus regius primarius, ' ' by Charles I. He was a horticulturist rather than a pure botanist, and his well-known book on garden plants, 'Paradisi in sole Paradisus Terrestris,' published in 1629, probably did much to stimulate interest in the cultivation of new and rare ornamental plants. Parkinson it was who had the boldness to depict the Garden of Eden on the title page of his 'Paradisus,' and includes among other remark- able products, the "Vegetable Lamb," a pineapple, and an opuntia, the two latter plants being, as far as we are aware, unknown in the Eastern Hemisphere before the discovery of America. Reference need only be made in passing to garden illus- trations from 1580 and onwards, and to such works as the 'Hortus Floridus' of Crispian de Passe, published in Hol- land in 1614, and to the numerous herbals that were being produced to show the great strides that had been made in horticulture and botany in Elizabethan and early Stuart times. The establishment of a botanic garden in Oxford in the year 1621, the nineteenth year of the reign of James I, is an 1 See Johnson, G. W. History of English gardening p. 98. London, 1829. 198 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 important landmark in the history of botanical progress in England and follows the lead already given by the founding of university botanic gardens on the Continent. Like them, it was ''primarily founded for a Nursery of Simples, and that a professor of Botanicey should read there and shew the use and virtue of them to his auditors." The founding of the Oxford Garden 1 was due to the munifi- cence of Henry, Lord Danvers, Earl of Danby, who acquired the lease of five acres of meadow land by the River Cherwell, near Magdalen College, and arranged that the University should lease the ground from the College, to whom it belonged. The land was considerably raised to prevent flooding, at great expense, and was surrounded by a wall which was completed about 1632. ft Access to the Garden was by means of the Danby gateway, the foundation stone of which was laid with all fitting cere- mony on St. James' Day, 1621, by the Vice-Chancellor of the University. 2 The following is taken from Vines and Druce - 3 "Botanic Lecture*. "The next Lecture that must bo mentioned is that of Botan- icey: but before I speak anything of its institution and settle- ment, I think it convenient that somewhat should be said of the Physic Garden, because 'twas primarily founded for a Nursery of Simples, and that a Professor of Botanicey should read there, and shew the use and virtue of them to his Auditors. "Henry Lord Danvers therefore, Baron of Dauntsey in the County of Wilts and Earl of Danby in Yorkshire, sometime a Gent. Com. of Christ Church, being minded to become a Bene- factor to the University, thought i better laid out than to begin and finish a place whereby learn" ing, especially the Faculty of Medicine, might be improved. At length selecting a place without the East Gate of Oxford, near the river Cherwell, which was then meadow ground, and 1 Daubeny, C. The Oxford Botanic Garden, popular guide. Oxford, 1850; Giinther, R. T. Oxford hardens. Oxford, 1912; Vines, S. II., and Druce, G. C. An account of the Morisonian Herbarium, etc. [Introduction.] Oxford, 1!)14. "The date of the founding of the Garden has usually been incorrectly given as 1G32, the year of the completion of the gateway, and in the account given by Wood of the foundation of the Garden there is a mistake of 1622 for 1021, but in their interesting epitome of the history of the garden, Vines and Druce show clearly that 1021 is the correct date when the ground was handed over and dele- gates were appointed. 8 hoc. cit. pp. IX-X. 1915] HILL BOTANIC GARDENS 199 had in ancient times been a Cemitery for the Jews of Oxon, gave to the University £250 to make a purchase of it. Upon the receipt of it they bought out the present possessor thereof, Mar. 27, 19 Jac. Dom. 1622; and not long after the University took a lease of the said ground from Magdalen College (for to them it did belong) in their own name July 28 following, by pay- ing yearly for it 40s. Afterward much soil being conveyed thither for the raising of the ground to prevent the overflowing of the waters, the first stone of the fabric was laid on the day of St. James the Apostle (July 25) an. 1622, after this manner: About two of the clock in the afternoon, the Vicechancellor with certain Heads, Doctors, and both the Proctors, went solemnly from St. Mary's Church to that place ; where being settled, Mr. Edward Dawson, a Physician of Broadgates, spoke an elegant Oration ; which being done, Dr. Clayton, the King's Professor of Medicine, spake another. Afterward the Vicechancellor laid the first stone with the offering of money thereon, according to the ancient custom; then several Doctors and both the Proctors; which being done, the Vicechancellor concluded with a brief Oration. "Afterward the said Earl proceeding in building and encom- passing it with a stately free-stone wall; which being almost finished, set up in front thereof, next to the East Bridge, a comely Gatehouse of polisht stone; on which for the perpetua- tion of his name, he caused this Inscription to be engraven on the out and inside thereof: GLORIAE DEI OPT. MAX. HONORI CAROLI REGIS IN USUM ACAD, et REIPUB. HENRICUS COMES DANBY D. D. MDCXXXII. In the year 1633 all the wall being finisht, and soon after the floor raised, which cost the Earl £5,000 and more, he caused to be planted therein divers simples for the advancement of the Faculty of Medicine. All which and several hundred more ni An interesting plan of the Garden by Loggan, made in 1675, shows four main enclosures within the boundary wall, each containing four series of geometrically arranged beds according to the formal arrangements then in vogue. Thomas Baskerville 1 gives the following description of the early condition of the Garden (about 1670-1700) : " Amongst ye severall famous structures & curiosities where- with ye flourishing University of Oxford is enriched, that of ye Publick Physick Garden deserves not ye last place, being a 1 Account of Oxford Collectanea (c. 1670-1700). [Vol. 2 200 ANNALS OF THE MISSOURI BOTANICAL GARDEN matter of great use & ornament, prouving serviceable not only to all Physitians, Apothecaryes, and those who are more immedi- ately concerned in the practice of Physick, but to persons of all qualities seruinjj; to help ye diseased and for ye delight & pleasure of those of perfect health, containing therein 3,000 seuerall sorts of plants for ye honor of our nation and Univer- sitie and service of ye Commonwealth." A further interesting piece of information given by Basker- ville is as follows : "Anno 1670. Here w T as built by the Income of the money given by the ffounder a fair greenhouse or Conservatory to pre- serve tender plants and trees from (he Injury of hard winter." This conservatory covered with a roof of stone slates is shown in Loggan's plan and was of sufficient solidity to be transformed early in the eighteenth century into the her- barium, library, and professorial residence, but it was subse- quently demolished. The conservatory was heated in severe weather by means of a four- wheeled fire-basket, or wagon filled with burning charcoal, which was drawn backwards and forwards along the path by a gardener. 1 Similar conservatories, or orangeries, were common in English gardens, and the building now used as a Museum (No. Ill) at Kew, was erected as an orangery in 1760. The first wooden greenhouses ever made were those erected at Oxford, in 1734, on either side of the Danby Gate. 2 Although the Garden was founded in 1621, it appears that some twenty years elapsed before Jacob Bobart was appointed the first gardener, owing probably to delays caused in prepar- ing the site. Under his supervision the Garden attained a con- siderable reputation and was visited by many distinguished people, including Evelyn and Pepys. Bobart *s catalogue of the plants cultivated, published in 1648, enumerates 1,600 plants, 600 of which were British, and many Canadian; it may be taken as evidence of his successful management of the Garden. 1 See Gardeners' Chronicle N. S. 23:73*2. f. 168. 1886. The figure is repro- duced in Giinther, R. T. Oxford Gardens p. 92. Oxford and London, 1912. 2 See engraving in Oxford Almanac, 17<>(>; reproduced in Giinther, loo. cit., plate facing p. 153. 1915] HILL — BOTANIC GARDENS 201 Owing to the outbreak of the Civil Wars and the death of the Earl of Danby, in 1644, his intention to provide the Uni- versity with a Professor of Botany as well as with a physic garden and a gardener, was long delayed, and the first profes- sor, in the person of Dr. Robert Morison, was not elected to fill the office until December 16, 1669. Morison 's first lecture was given in the Medicine School on September 2, 1670, and on September 5, he ''translated himself to the Physic Garden where he read in the middle of it (with a Table before him) on herbs and plants for five weeks space, not without a con- siderable Auditory." 1 Space does not permit us to follow the fortunes of the Ox- ford Garden or to make mention of the many distinguished professors associated with it since its foundation, but it is of interest to remember that Sir Joseph Banks was a student at Christchurch, from 1760 to 1763, in the days of Sibthorp's professorship, a time when no lectures on botany were given and the subject was much neglected in the University. Banks was so keenly interested in botany that he applied to Sibthorp for permission to procure a qualified lecturer to be paid entirely by the students. This request being acceded to and a sufficient number of students having been obtained, Banks went to Cambridge and secured the services of a Mr. Lyons, a botanist and astronomer, for the purpose. 2 The assistance rendered by the sister university in the botanical education of one who was to achieve such great things for the science and to have so large a share in directing the fortunes of the Royal Gardens at Kew, is worthy of more particular notice since botany was not officially recognized in Cambridge until 1724, when a professor was appointed, and there was no botanic garden there until the year 1762. The Botanic Garden at Edinburgh, which now claims atten- tion, has had a somewhat involved history, as the present Royal Botanic Garden is the sixth and only remaining botanic garden in the Scottish capital, though in the early years of 1 Vines, S. H., and Druee, G. C. loc. cit., p. XXIV. 'Anonymous, Sir Joseph Banks and the Royal Society p. 62. London, 1844. [Vol. 2 202 ANNALS OF THE MISSOURI BOTANICAL GARDEN the eighteenth century there were three distinct gardens in Edinburgh. The original Edinburgh Garden was founded by Sir Robert Sibbald and Sir Andrew Balfour, physicians, for the cultiva- tion of medicinal plants in order "to safeguard the Practi- tioner against the Herbalist and to enable him to have a cor- rect knowledge of the plants which were the source of the drugs he himself would have to compound." 1 For this purpose they acquired the lease of a small area of ground near Holyrood, and James Sutherland was secured to look after it and instruct the apprentices and lieges in botany. Such success attended the venture that a piece of the Royal Flower Garden at Holyrood was assigned to the cultivation of medicinal plants and this with the title of Physic Garden be- came the Royal Botanic Garden in Scotland. In 1767 the same physicians acquired from the Town Council of Edinburgh a lease of the Garden of Trinity Hos- pital and adjacent ground — a site now partly occupied by the Waverley Station — and Sutherland was appointed to lec- ture on botany as Professor in the Town's College, now the University, and to be in charge of this new Physic or Town's Botanic Garden. Then in 1702 another botanic garden was established by the University — the College Garden — of which Sutherland was also placed in charge. The distance of the two existing gardens being too great from the University, Sutherland resigned the care of the Town's Garden and Col- lege Garden in 1706, but remained King's Botanist, retaining the Keepership of the Royal Botanic Garden, and the Town Council appointed a professor to take charge of the Town and College Gardens. There were thus two rival botanical schools with their gardens in Edinburgh, and it was not until the year 1739 that the rivalry was terminated by the appointment of Dr. Charles Alston, the then Keeper of the Royal Botanic Garden, to the University Chair — a combination which holds to the present day by consent of the Crown and the University. 1 Balfour, I. Bailey, History of the Royal Botanic Garden, Edinburgh. Notes of the Roy. Bot. Gard., Edinburgh 4: 1904. Historic Notice, pp. v-viii. 1915] HILL BOTANIC GARDENS 203 Between the years 1760 and 1786 a new site was found for a botanic garden and the other gardens were abandoned. This new garden, formed during John Hope's keepership, eventu- ally became unsuitable owing to the growth of the town, and the present site (twenty-seven acres) was selected about 1820, during the keepership of Professor Graham. The Edinburgh Garden, through the University, still retains its connection with the Medical School, and the instruction of the medical student is one of the functions of the Professor and his staff. With its fine collections of living plants, its herbarium, library, laboratories, and remarkable series of specimens in the museums, the Edinburgh institution may well serve as an example of the ideal botanic garden. The Chelsea Physic Garden, 1 which next claims attention, was founded as the Garden of the Society of Apothecaries 2 in London in the year 1673. The earlier garden of the Society had been at "Westminster, but this had no river frontage, and the ground at Chelsea was leased from Charles Cheyne, in 1 673, as a convenient spot for building a barge house for their processional barge in which they attended city functions, as was customary for city companies. In 1676 the plants at Westminster were moved to the Chelsea Garden, which had already been suitably enclosed with a wall. The freehold of the Manor of Chelsea, including the Physic Garden, was purchased in 1712 by Dr. (after- wards Sir Hans) Sloane, who in the year 1722 conveyed the Garden by deed to the Society of Apothecaries. The convey- ance was made "to the end that the said garden might at all times thereafter be continued as a Physick Garden, and 1 Field, H., and Semple, R. H. Memoirs of the Botanic Garden at Chelsea. London, 1878. 2 The Society of Apothecaries itself was formed in 1617 "that the ignorance and rashness of presumptuous Empirics and unexpert men might be restrained, whereby many discommodities, inconveniences and perils do daily arise to rude and incredulous people." See Blunt, R. Cheyne Walk and thereabout p. 99. London, 1914. Certain continental botanic gardens, such as the ancient garden at Salzburg were founded in connection with local pharmaceutical schools and have had no connection with any university. [Vol. 2 204 ANNALS OF THE MISSOURI BOTANICAL GARDEN for the better encouraging and enabling the said Society to support the charge thereof, for the manifestation of the power, wisdom, and glory of God in the works of the creation, and that their Apprentices and others might better distinguish good and useful plants from those that bore resemblance to them, and yet were hurtful and other the like good purposes." 1 The utilization of the Garden for the sole purpose of grow- ing medicinal plants to be converted into drugs for the Society's use was prohibited by Sir Hans Sloane's deed of gift, and he definitely encouraged the science of botany by making it a condition that fifty specimens of distinct plants, well dried and preserved, which grew in their garden that same year, with their names and reputed names, were to be delivered yearly to the President and Fellows of the Royal Society of London, "until the number of two thousand had been attained." He also enjoined that the plants so presented in each year were to be specifically different from those pre- sented in every former year; and this injunction was more than faithfully carried out by the Society. 2 The Garden achieved some notoriety in having been the first garden in England where the Cedar of Lebanon was planted; the final survivor of the four placed there in 1683 was only removed in the year 1904. John Evelyn, who visited the Garden in 1685, was impressed by the heating arrangement of the greenhouses, then quite an innovation. "What was very ingenious," he remarks in his diary, "was the subterranean heate conveyed by a stove under the conservatory, which was all vaulted with bricks, so as he has the doores and windows open in the hardest frosts, seclud- ing only the snow." An arrangement far more efficient and useful than the remarkable open fire-baskets formerly in use at Oxford. 1 Perrfrles, P. E. F. London Botanic Gardens. Wellcome Chemical Research Laboratories, London, Publ. 62: p. 57. London, 1906 (transferred from the present to the past tense). 2 . Johnson, G. W. History of English gardening p. 150. London, 1820. 3 3 John Watts, appointed gardener in 1680. MS] HILL BOTANIC GARDENS 205 The appointment of Philip Miller, 1 in 1723, as Head Gard- ener, is an important event in the history of the Garden, both for the value of his services to the Garden itself and for his widespread influence on botany and horticulture. At the time of Miller's appointment, exotic plants were pouring in from every clime under the patronage of a general taste for their acquisition. Hothouses were multiplying and their inhabitants accumulating to a hitherto unheard-of ex- tent, and a man of Miller's practical skill and botanical knowl- edge was needed not only to demonstrate his skill, but also to impart his knowledge for the use of others. From his 'Dic- tionary' it can be seen that many plants were grown and flowered at Chelsea for the first time under cultivation. William Aiton (1731-1793), the first Curator of the Royal Gardens at Kew, was a pupil under Miller at Chelsea, nor must Nathaniel Bagshaw Ward, Examiner to the Society of Apothecaries from 1836 to 1854, the inventor of Wardian cases, be forgotten. His invention made possible the intro- duction of the tea plant to India by Robert Fortune ( Curator of the Chelsea Garden, 1846-1848), of Cinchona from South America to Kew by Markham, and thence to India, and of many other valuable products to botanic gardens which have subsequently been disseminated for the use of mankind. Not the least useful of the activities of the Chelsea Physic Garden were the herborizing excursions around London, under the charge of the Demonstrator of Plants, which were maintained for some two hundred years. The Physic Garden has suffered Diany vicissitudes in the course of its existence, and towards the end of the last century almost ceased to exist, but for- tunately a new arrangement for its maintenance was made in 1899. 2 Reorganized under the new scheme and with its modern greenhouses and laboratory, the Chelsea Garden has entered on a sphere of usefulness in connection with the teach- ing of botany and the provision of material and opportunity 1 Charles Miller, son of Philip (who had aided in the selection of the site), was made first Curator of the original Cambridge University Botanical Garden founded in 1762. 2 The Chelsea Physic Garden. First Report of Committee of Management, 1905, with plan of the Garden in 1753. 206 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 for botanical investigation as great if not greater than at any time in the past. The origin of the Royal Botanic Gardens, Kew, was due to the interest in botany displayed by Princess Augusta, Princess Dowager of Wales, under the guidance of Lord Bute, an enthu- siastic botanist; and a piece of the Royal Garden attached to Kew House was set apart in 1760 for the purpose of forming a physic garden. "The space allotted consisted originally of nine acres, enclosed by walls (the ornamental building now standing, called the Temple of the Sun, being then nearly the centre of the Garden), which was laid out and scientifically planted in two divisions, one containing a collection of herbaceous plants, arranged ac- cording to the Linnean system, then in its infancy, but with which Aiton had become well acquainted while serving under Miller. This division was called the Physic Garden. "The second division was called the Arboretum, containing all the then known introduced hardy trees and shrubs scien- tifically arranged. Within the area were several Glass houses, and in 1761 a large hothouse, 110 feet long, was erected by Sir Wm. Chambers . . in after years known as the Great Stove. In the same year an Orangery, 130 feet long, was also erected.' n No doubt several of the old and interesting trees now stand- ing near the Temple of the Sun were planted in Princess Augusta's arboretum soon after the foundation of the Garden. William Aiton was placed in charge of the Garden under the direction of Lord Bute, and was Chief Gardener from 1759 to 1793, Sir W. Chambers, the designer of the Pagoda and most of the Temples still to be seen in Kew, gives the follow- ing account of Princess Augusta's Physic Garden: "The Physic or exotic garden was not begun before the year 1760; so that it cannot possibly be yet in perfection; but from the great botanical learning of him who is the principal man- 1 Smith, John. Records of the Royal Rotanic Gardens, Kew. p. V. 18S0. See also Kew Bull. Misc. Inf. 1891:289-294. 1891. The Great Stove stood near the Temple of the Sun and was removed in 1861. Its site is marked by an old wistaria, trained on an iron cage which grew upon its walls. The method of ventilating the house was designed by William Hales, the physiologist, who described his method in a letter to Linnaeus written in 1758. The method is in use at Kew to-day and was devised independently by Sir W. T. Thiselton-Dyer. The Orangery is now Museum No. III. 1915] HILL BOTANIC GARDENS 207 siduity m expense, it may be concluded that in a lew years this will be the amplest and best collection of curious plants in Europe." 1 With the death of Princess Augusta in 1772, George III in- herited the Kew property and united the gardens of Kew House with those lying contiguously, which formed the gar- dens of the Palace of Richmond, and so produced the extensive domain now occupied by the Royal Botanic Gardens. To the great benefit of Kew, George III chose Sir Joseph Banks as his botanical adviser, and for forty-eight years Sir Joseph directed the affairs of the Gardens. During his term of office the practice of sending out collectors was established, a prac- tice fraught with discoveries of wide- spread interest and value for horticulture and botany. Of the many Kew collectors 2 it is well to mention in particular the following : Francis Masson, the famous collector of Cape plants; David Nelson, assistant botanist on Cook's third voyage, who subsequently died from exposure after the mutiny of the Bounty ; Archibald Menzies, who travelled in Australia and Chili and introduced Araucaria imbricata; William Ker, the collector in China, who in 1812 became Superintendent of the Royal Botanic Garden, Ceylon ; and Allan Cunningham, whose travels took him to Brazil, the Cape, Australia, Tasmania, New Zealand and Norfolk Island. Cunningham returned to Australia, in 1836, to fill the post of Superintendent of the Botanic Garden at Sydney. The days of Sir Joseph Banks were indeed the Golden Age of Kew, and under his direction the Royal Gardens became a center of botanical exploration and horticultural experiment paralleled before The well-known lines of Eras mus Darwin 3 refer to the Kew of Sir Joseph Banks' day, en- riched by the labors of her collectors : 1 Chambers, Sir W. Plans, elevations, sections and perspective views of the gardens and buildings at Kew in Surrey, the seat of Her Royal Highness, the Princess Dowager of Wales p. 3. Brentford, 1765? a For the complete list of Kew collectors, see Kew Bull. Misc. Inf. 1891: 295-311. 1891. 8 The Botanic Garden. 1791. 208 [Vol GARDEN "So sits enthroned, in vegetable pride, Imperial Kew by Thames' glittering side; Obedient sails from realms unfurrow'd bring For her the unnam'd progeny of Spring; Attendant Nymphs her dulcet mandates hear, And nurse in fostering arms the tender year ; Plant the young bulb, inhume Hie living seed, Prop the weak stem, the erring tendril lead; Or fan in glass-built fanes the stranger flowers, With milder gales, and steep with warmer showers. Delighted Thames through tropic umbrage glides, And flowers antarctic, bending o'er his tides; Drinks the new tints, the sweets unknown inhales, And calls the sons of Science to his vales." George III and Sir Joseph Banks both died in 1820, and for some twenty years the Royal Gardens gradually fell into a condition of sad neglect. In the early years of the reign of Queen Victoria, however, the Royal Gardens were restored to their proper position as the National Botanical Garden, thanks to the devoted labors of the committee of which John Lindley and Sir Joseph Paxton were the distinguished mem- bers, and Sir William Hooker was appointed Director of the Royal Botanic Gardens in 1841. Thence onwards, under Sir Joseph Hooker, and Sir William Thiselton-Dyer, the history of Kew has been one of steady progress and usefulness and the Royal Botanic Gardens have played a prominent part in connection with all matters of botanical enterprise in the British Colonies. 1 1 The establishment at Kew comprises: I. The Botanic Gardens and Arbo- retum (288 acres) ; II. The Herbarium and Library; III. The Museums devoted to (i and ii) dicotyledons and monocotyledons and their economic products, (iii) exotic timbers and conifers, (iv) British forestry, and (v) The North Cillery of paintings by Mis3 Marianne North; IV. The Jodrell Laboratory for scientilic research; V. The Pathological Laboratory; VI. Director's Office. The more important books dealing with the history of Kew and its collec- tions are: 1. Aiton, W. Hortus Kewensis, 3 vols. London, 1789. 2. Aiton, W. T. Hortus Kewensis, 5 vols. London, 1810-13. [2nd ed.] 3. Scheer, F. Kew and its Gardens. Richmond, 1840. 4. Historical account of Kew to 1841. Kew Bull. Misc. Inf. 1891-270-327. 1891. 5. Royal Botanic Gardens, Kew, Reports on progress and condition. 1855-1882. 6. Perredes, P. ]5. F. London Botanic Gardens. Wellcome Research Labora- tories, London, Publ. 62: 17-40. 1 !)()(!. 7. Bean, W. J. The Royal Botanic Gardens, Kew. London, 1908. 8. Popular Official Guide to the Royal Botanic Gardens. Kew, 1912. 9. Kew Bull. Misc. Inf. 1887- 10. Kew Plant Lists and Museum Guides. 11. Smith, J. Records of the Royal Botanic Gardens, Kew. London, 18S0. 1915] HILL — BOTANIC GARDENS 209 Kew, having no connection with any university or educa- tional establishment, 1 differs markedly in this respect from the botanic gardens to which allusion has been made. Her sphere of usefulness is largely concerned with the economic aspect of botany, and it is her aim and object to encourage and assist, as far as possible, scientific botanists, travellers, merchants and manufacturers, in their varied botanical in- vestigations. Space does not permit of more than a brief mention being made of the new Berlin Garden at Dahlem and of many other important gardens on the Continent and in Great Britain and Ireland. The Berlin Botanic Garden 2 was founded in 1679 in the heart of the city, and in 1801 it was reorganized and im- proved. The removal of the Garden to its present site at Dahlem was completed in 1909. The new Garden with its geo- graphical and ecological arrangements of the plants and the splendid Botanical Institute and Museums, now forms one of the finest schools of botany in the world. In her aims and objects she compares more closely to Kew than to any other botanic garden. The following notes refer to other important gardens not specifically men- tioned in the text: The Upsala Garden (founded 1655-57) was injured by the great fire in 1702, and remained neglected until 1741. The restoration was begun by Rosen and energetically taken up by Linng. (See Swerderus, M.B. Botaniska Tragarden, Upsala, 1655-1807. Falun, 1877.) The Imperial Botanic Garden of Peter the Great, Petrograd (St. Petersburg), was founded in 1713 (see Kew Bull. Misc. Inf. 1913:243-252. 1913), and that of Vienna in 1754. The Cambridge Botanic Garden was founded in 1762 by Richard Walker, D.D., formerly Vice-Master of Trinity College. The Garden was transferred to its present site in 1846 and occupies about twenty acres. It is in close connection with the Botany School at Cambridge and provides abundance of material for research work and for the teaching purposes of the Botany School. The Garden is also fitted with a small laboratory. Some eighteen acres are available for extension. 1 Lectures and demonstrations in chemistry and physics, general botany, systematic and geographical botany, economic botany, plant pathology and on soils and manures are given in the Gardens to the young gardeners at Kew. 2 See Urban, I. Geschichte des Konigl. botanischen Gartens und des Konigl. Herbariums zu Berlin, nebst einer Darstellung des augenblicklichen Zustandes dieser Institute. Festschr. naturwiss. u. med. Staatsanst. Berlin, 1881. Engler, A., and others. Der Kgl. bot. Garten und das Kgl. bot. Museum zu Dahlem. Berlin, 1909. [Vol. 2 210 ANNALS OF THE MISSOURI BOTANICAL GARDEN The Royal Botanic Gardens, Glasnevin, Dublin, were founded in 1790, through the influence of Dr. Walter Wade and the Hon. Dublin Society, and in 1877 were transferred to the Science and Art Department. The Botanic Garden of Trinity College, Dublin, was established in 180(5-08. (See Notes from the Botanical School of Trin. Coll., Dublin l:p. 3. 1890.) The garden at Breslau waa founded in 1811. The Geneva Garden, founded in 1817, has recently been transferred to a new site. The Munich Garden was founded in 1822 (see Martius, Hort. Bot. R. Acad. Monacensis p. 5. 1825.) It is now one of the most interesting gardens on the Continent and forms an integral part of the new and magnificently equipped Botanical Institute. The Glasgow Botanic Garden was established in 1817, having been preceded by an earlier Physic Garden; in 1841 the garden was moved to its present site and now occupies about forty acres (see Sherry, C. The Glasgow Botanic Gardens. Glasgow, 1901). The botanic gardens whose history has been sketched in the preceding pages can all trace back their origin to the herb gardens of mediaeval times and the physic gardens of the early universities. Their raison d'etre, the growing of simples for the medical profession, has resulted in the exploration of the globe for the useful, the beautiful, and the curious in the vegetable kingdom. A few other botanic gardens, how- ever, remain to be considered, whose origin must be traced to a different motive. These gardens lie within the tropics, and the desire to participate in the valuable trade in spices, then a monopoly of the Dutch, led to the establishment of gardens for the cultivation of various spices and other im- portant economic plants during the latter part of the eighteenth century. The credit of establishing economic gardens in the tropics belongs to Great Britain, and the experiment, started with the founding of the botanic garden in the Island of St. Vincent, in 1764, has been continued, at times somewhat intermittently, until at the present day a botanic garden or station is to be found in almost every British dependency and possession. The lead given by Great Britain has been followed by other nations and several notable achievements have resulted. Foremost among these must be mentioned the Botanic Gardens at Buitenzorg, Java, 1 probably the most complete and exten- 1 The complete institution at Buitenzorg, known as "Lands Plantentium," is divided into nine Departments: I. Herbarium and Museum; II. Botanical 1935] HILL BOTANIC GARDENS 211 sive botanical establishment in the world. The garden was founded in 1817 at the suggestion of Reinwardt, 1 and Dr. C. L. Blume was appointed the first Director when Eeinwardt left Java to become Professor at Leiden. The first Curator, James Hooper, had been trained at the Royal Gardens, Kew. The valuable scientific researches in pure and applied botany carried out at Buitenzorg are too well known to require de- tailed description, and allusion need only be made to the im- portant encouragement given to the cultivation of Cinchona, rubber, coffee, and other economic products in Java, through the medium of the Botanic Gardens. The earliest tropical botanic garden appears to have been that founded in the West Indies at St. Vincent, in 1764. 2 A garden of about forty acres was established with Government House in the center, as a place where plants " useful in medi- cine and profitable as articles of commerce might be propa- gated and where nurseries of the valuable productions of Asia and other distant parts might be formed for the benefit of His Majesty's Colonies." Plants intended for the West Indies were lost owing to the mutiny of the Bounty in 1790, but three years later Captain Bligh succeeded in landing a valuable consignment of plants from the Pacific, including the bread fruit, and a few years after, nutmegs, cloves, and other spice plants were introduced. Until 1815 the Garden flourished, when interest was shifted to Trinidad, where a garden was formed in 1817, and many Laboratories ; III. Agricultural and Experimental Garden (151 acres) with laboratory for agricultural chemistry; IV. Pharmacological Laboratory; V. Botanic Garden (145 acres), Mountain Garden (77 acres and 700 acres virgin forest), and Laboratory; VI. Office, Library, and Photographic Laboratory; VII. Forest Flora collections; VIII. Laboratory for the study of Deli tobacco; IX. Coffee Experiment Station (the two last are partly private institutions). 1 It is possible that the original idea of founding a botanic garden at Buitenzorg was made by Sir Stamford Raffles, when Governor of Java, during the few years (1811-17) that Java was a British possession. Near the entrance there is a small monument to the memory of Lady Raffles, who died in Java during the British occupation of the island. * Guilding, Rev. Lansdown. An account of the botanical garden in the island of St. Vincent. Glasgow, 1825. See also Kew Bull. Misc. Inf. 1892:92-104. 1892. [Vol. 2 212 ANNALS OF THE MISSOURI BOTANICAL GARDEN 1 of the plants were removed thence from St. Vincent. The St. Vincent Garden was restored in 1890 and now, fortunately, there is a botanic garden or station in every West Indian island of importance. These serve as centers for the distri- bution of economic plants and of scientific information, and have also become gardens of peculiar charm for the refresh- ment and recreation of the inhabitants. The gardens of the East, however, are preeminent among tropical botanic gardens owing to the vastness of the territory over which they exercise their influence. Foremost among these, after Buitenzorg, is the Calcutta Botanic Garden, founded in 1786 on the suggestion of Lieut. Col. Robert Kyd. This garden was intended to be the source of botanical in- formation for the possessions of the East India Company, and also the center to which exotic plants of economic interest could be imported for experimental cultivation and thence distributed. It was hoped at first that the spices which rendered the trade of the East India Company with the Moluccas, etc., so lucrative, might be cultivated in Bengal, and Kyd's earliest efforts were directed to the introduction of cloves, nutmegs, cinnamon, and pepper vines, but the climate of northern India proved unsuitable. Much was attempted and, despite numer- ous failures, much accomplished in the way of new introduc- tions in the early days, the failures possibly being as import- ant as successes since it was soon evident what could or could not be grown in Bengal. The Calcutta Gardens, however, despite the failure in their original intention, have under their distinguished superintendents achieved notable results. The introduction of tea to India — one of Kyd's original ideas was mainly carried out through the instrumentality of the Gardens, and potato growing, the introduction of mahogany, jute, sugar-cane, and the improvement of Indian cotton culti- vation, may be counted among its many benefits to the people of India. 1 King, George. Guide to the Royal Botanic Garden, Calcutta. 1895. 1915] HILL — BOTANIC GARDENS 213 But most important of all was the part played by the Garden in the introduction of Cinchona 1 from South America to India with the cooperation of Kew, and the subsequent cultivation of Peruvian bark in the Sikkim Himalaya. The Calcutta Garden in this particular has retained the ancient connection of botanic gardens with medicine perhaps more than any other similar institution. The cultivation of the quinine- yielding cinchonas has been carried to such a successful issue in the plantation and factory at Sikkim under the superintend- ents of the Garden, notably Sir George King, that government hospitals and dispensaries have for years been supplied from this source with all the quinine required for them; while 5-grain doses of the same drug can be purchased for a pice each (equal to about |d. English) at every post-office in the Province. 2 Associated with the Garden are the valuable herbarium and the economic museums, the whole forming an institution capa- ble of responding fully to the botanical requirements of the Indian Empire. The history of botanic gardens would be incomplete without reference being made to the foundation of such institutions in Malaya and Ceylon. At Penang 3 the Hon. East India Company decided to start spice gardens with a view of break- ing down the Dutch monopoly. Living plants of nutmegs and cloves were collected in the Moluccas in 1796, and the first nutmegs were produced in Penang in 1801. The Gardens, however, were destroyed 4 in 1805, and re- founded in 1822 at the instance of Sir Stamford Baffles. He it was who founded the Singapore Gardens in 1823, and intro- 1 See Markham, Sir C. R. Peruvian Bark. London, 1880. 2 Guide to Royal Botanic Garden, Calcutta p. 6. 1902. [Revised ed.] • Ridley, H. N. The abolition of the Botanic Gardens of Penang. Agr. Bull. Straits and Fed. Malay States 9: p. 97. 1910. * Ibid. p. 104. founded abolished First Penang garden 1800 1805 Second Penang garden 1822 1826 Third Penang garden 1884 1910 First Singapore garden 1823 1829 Second Singapore garden 1878 and still existing [Vol. 2 214 ANNALS OF THE MISSOURI BOTANICAL GARDEN duced nutmegs, cloves, and cacao, but the Garden was un- fortunately abolished in 1829. The botanical enterprise of this remarkable man in Java, Malaya, and Sumatra, deserves an honorable place in our botanical history, and no more fitting memorial of his genius could be found than the present beautiful garden at Singa- pore, founded in 1878, which has so ably upheld the best tra- ditions of the founder of the original garden. The first botanic garden established in Ceylon 1 was cre- ated by the Dutch on Slave Island, near Colombo, but this was neglected when the island passed into the possession of Britain, and it was not until 1810, when Sir Joseph Banks suggested a site, that a new garden was established, also on Slave Island at a place still known as Kew. William Ker was transferred from Canton, in 1812, and appointed superin- tendent. The Garden was not a success, owing to its situation, and in 1821, during the superintendence of Alexander Moon — who had been sent out by Banks — the Garden was transferred to Peradeniya. In its new site its history has been a record of prosperity, and its usefulness has been considerably in- creased by the formation of additional gardens in different parts of the island suitable to the varied climatic conditions of the country. The scientific researches in pure and applied botany, in tropical mycology and chemistry, and the cultural experi- ments which have been carried out in the Gardens and labora- tory in Ceylon have thoroughly justified the existence of the institution at Peradeniya, and prove, if proof were needed, the inestimable value of scientific botanical establishments in the tropics. The colonizing of Australia soon led to the foundation of botanic gardens, and those at Sydney 2 have the honor of being the first to be founded in the Australian Continent. 1 Trimen, Henry. Hand guide to the Royal Botanic Gardens, Peradeniya. Colombo, 1885. 'Sydney Botanic Gardens. Kew Bull. Misc. Inf. 1906: 205-218. 1906. Maiden, J. H. Presidential address to the Royal Society of New South Wales, 1912. Roy. Soc. N. S. Wales, Jour, and Proc. 46: 1-73. 1912. [See p. 49.] 1915] HILL BOTANIC GARDENS 215 These Gardens occupy the site of the Government Garden established in 1788, and here the first exotic plants were in- stalled in the same year. Owing to the great demand for New Holland plants, due largely to the interest taken in them by Sir Joseph Banks, a vigorous exchange in plants soon grew up between the Sydney Gardens and the outside world, to the great profit of the institution, which appears to have been definitely founded as a botanic garden in the year 1816. Sydney is now fully equipped for botanical work with its renowned Botanic Gardens, its university department of botany, and museum. Other well-furnished botanic gardens are to be found at Brisbane, Melbourne, Adelaide, Hobart, and Tasmania; at Melbourne and Adelaide their value is enhanced by associa- tion with the botanical departments of the universities. Flourishing botanic gardens are also established in New Zealand, at Wellington, Dunedin, Napier and Christchurch. 1 Before leaving the subject of botanic gardens in British Dominions, mention must be made of the foundation only last year (1913) of the National Botanic Garden of South Africa, at Kirstenbosch, 2 which, though the most recent of such gardens, bids fair to take a place in the front rank of the botanic gardens of the world, both on account of the admirable nature of the site and the remarkable character of the South African flora. The predecessor of this garden was the Cape Town Botanic Garden, founded in 1848, which became the Municipal Garden of Cape Town in 1892, after a somewhat chequered career. 3 The Municipal Gardens at Durban, Natal, established in 1853 as the Natal Botanic Garden, have played an important part in botanical enterprise in South Africa and at no time more than under the directorship of Dr. J. Medley "Wood. It 1 The Botanic Gardens at Hong Kong with their herbarium form a valuable center for Asiatic botany, nor must the Gardens at Tokyo and other important Japanese centers of botanical activity be omitted. Botanic gardens have been established also in Fiji, Seychelles, Mauritius, etc. »Kew Bull. Misc. Inf. 1913: pp. 309-314, and p. 373. 1913; Nature 93: 190-191. 1914. •Kew Bull. Misc. Inf. 1892: 10-14. 1892. [Vol. 2 216 ANNALS OP THE MISSOURI BOTANICAL GARDEN would be a most unfortunate occurrence should the activities of this important garden, small though it is, be in any way curtailed or its functions abrogated by the change in its ad- ministration or owing to the establishment of the new National Garden. 1 In America, 2 botanic gardens have been in existence since the year 1728, when John Bartram founded a botanical garden in Philadelphia. Though no longer a botanic garden, the plot of ground still remains and serves as an interesting landmark in the history of North American botany. 3 The foundation of the Elgin Botanic Garden by Dr. David Hosack, in 1801, was an important advance and the Garden of some twenty acres was gradually stocked with a large and valuable collec- tion of plants. 4 In 1810 it became the Botanic Garden of the State of New York and was subsequently granted to Columbia College. It has ceased to exist as a garden, but it will be always held in remembrance from its association with the work of its founder, of Amos Eaton, John Torrey, and Asa Gray. The founding of the New York Botanical Garden, as a result of the untiring energy of Dr. N. L. Britton and the Torrey Botanical Club, may be regarded as a worthy monu- ment to the memory of these pioneers in American botany. Furnished as it is with the Torrey Herbarium, the value of which has been enhanced by vast acquisitions— including the Chapman and Meisner herbaria—, the library, museum, and laboratories, the New York Botanical Garden, in association with the Department of Botany of Columbia University, rivals 1 Other botanic gardens and stations in Africa have been established in Uganda, in the British and French West African Colonies and at Victoria in the German Cameroons. In Algeria there is the fine old "Jardin d'essai" at Algiers. * In Canada there is a botanic garden at Ottawa in connection with the Agri- cultural Department, and a small garden at Montreal belonging to the botanical department of McGill University. * Bartram, through Peter received Philip Miller of the Chelsea Physic Garden. See Wilbert, M. I. Some early botanical and herb gardens. Am. Jour. Phar. 80: 412-427. 1908. [See p. 416.] * Hosack, David. A statement of facts relative to the establishment and progress of the Elgin Botanic Garden, etc. New York, 1811. Wilbert, M. I. Loo. tit. p. 423. 1915] HILL — BOTANIC GARDENS 217 in its completeness, if it does not already excel, any botanical institution in the Old World. 1 The Botanic Garden of Harvard University, which was founded in 1805, next claims attention. The garden itself is small, but in combination with the herbarium containing Gray's collection, the museums, library, and laboratories, it forms a botanical institution singularly complete and efficient. With the Arnold Arboretum situated close at hand, Harvard has become a Mecca for botanists all the world over. The Arboretum, 2 founded by Mr. James Arnold, covers at present about two hundred and twenty acres, and the collection of trees and shrubs brought together by the remarkable industry of Professor Sargent is unrivalled, and it stands to-day for one of the most interesting and valuable developments of the prin- ciples of a botanic garden. To Professor Sargent, as well as to such enlightened men as the de Vilmorins and the firm of Veitch, the gardening world also owes a great debt of grati- tude for the introduction of countless new hardy plants for the enrichment of our gardens. Important work is being performed by the United States De- partment of Agriculture, at Washington, in the introduction of new plants, nor should the part played by the herbarium of the United States National Museum be forgotten in this connec- tion. Allusion may also be made at this point to the Desert Laboratory at Tucson, and to the importance of the experi- mental work which is being undertaken in Hawaii, Cuba, and the Philippine Islands. Other botanic gardens are those of the Michigan Agricul- tural College (1877), the University Botanic Garden at Berke- ley, California, the Botanic Garden of the University of Penn- sylvania at Philadelphia, of Smith College at Northampton, and the Buffalo Botanical Garden. These each and all are of recent foundation and have been established in response 1 Britton, N. L. Botanical Gardens. N. Y. Bot. Gard., Bull. 1: 62-77. 1897; Underwood, L. M. The department of botany and its relation to the New York Botanical Garden. Columbia Univ. Quart. 4:278-292. 1903; Britton, N. L. Botanical Gardens. Bull. Torr. Bot. Club 23: 331-345. 189(1. [See pp. 341-345.1 See also Britton, N. L. hoc. cit. pp. 72-77. *Kew Bull. Misc. Inf. 1910: 2G1-2G9. 1910. [Vol. 2 218 ANNALS OF THE MISSOURI BOTANICAL GARDEN to the need of such institutions for teaching and research in botany. Finally there is the Missouri Botanical Garden, 1 founded in 1889 by the munificence of Henry Shaw, in pious memory of whom this Twenty-fifth Anniversary Celebration is being held. Founded on broad lines and generously endowed, the Garden has already established itself as one of the important botanic gardens of the world. With its herbarium, library, and laboratories, and the close relationship with the Shaw School of Botany of Washington University, the future of the Missouri Botanical Garden cannot fail to be one of ever- increasing usefulness. It is a matter of regret to all botanists that South America, so rich a storehouse of botanical treasures, should contain so few important botanic gardens. The magnificent Garden at Rio de Janeiro, 2 founded in 1808, the Botanic Gardens at Santiago in Chili, H at Georgetown, British Guiana, and at Buenos Aires represent the measure of botanical enterprise in the continent. The botanical possibilities at Rio de Janeiro are very great, and the Garden, in addition to its collection of living plants, possesses the herbarium of Martius, a library and laboratories. When the interest in botanical science becomes fully aroused in Brazil, a striking development of the botanic garden may be confidently expected. 1 Trelease, W. The Missouri Botanical Garden. First annual report of the Director, for 1889. Mo. Bot. Gard., Rept. 1: p. 91. 1890. Trelease, W. The Missouri Botanical Garden. Pop. Sci. Month. 62: 193- 221. 1903. a Rodrigues, J. B. Hortus Fluminensis. Rio de Janeiro, 1894. 9 Philippi, F. Vorgeschichte des botanischen Gartens von Santiago. Garten- flora 31: 6—9. 1882. The date of the foundation of this garden is uncertain, herbarium and museum attached to the University. See also Philippi, F. It contains a very interesting collection of plants and trees, and there is a good Memoria i catalogo de Ins plantas cultivadas en el Jardin Botanico. Santiago de Chile, 1884. 1915] HILL BOTANIC GARDENS 219 Functions of Botanic Gardens The varied functions performed by botanic gardens in the course of their history have been indicated to some extent in the preceding pages, and the gradual change in function from that of the purely medicinal garden for the growing of simples to the fuller conception of the true botanic garden has been traced. With the increase in knowledge and interest in botany, new plants were brought into cultivation from all sources and gardens threatened to be overwhelmed by unarranged masses of material. Classification, therefore, became a necessity and various systems began to be put forward in response to the demand. To these we cannot do more than make brief allu- sion. After the efforts of Caesalpino came Morison's system of classification, which did not receive general acceptance and was absorbed into that of Ray, and neither system found many adherents as regards the disposition of plants in the botanic gardens. The two early systems which really dominated plant ar- rangement were those of Linnaeus and Jussieu, the latter finding acceptance in France, where the Linnaean system never became established. To France, in consequence, we must look for the evolution of the natural system of classification, and, with its adoption, botanic gardens gradually developed into a means of provid- ing a synoptical illustration of the whole vegetable kingdom. It was in the Trianon gardens that Bernard and A. L. de Jussieu, towards the close of the eighteenth century, evolved the idea of grouping plants according to a system based on natural affinities, and the Trianon system was quickly imitated and elaborated in course of time by Gartner, De Candolle, Robert Brown, and others. With the revival of interest in plant collecting a new development took place, and plant geography came to the front as a basis of plant arrangement in botanic gardens. Thus collections were made to represent the floras of definite regions, such as that of New Holland or The Cape, and af- [Vol. 2 220 ANNALS OK THE MISSOURI BOTANICAL GARDEN forded instructive and useful aids to the study of botany and plant distribution in particular. These two tendencies in botanic garden arrangement hold good at the present day, and gardens may be found adhering to one or the other plan. Both systems have their merits, and where possible both may be followed with due regard to local conditions, but a slavish adherence to the one or to the other tends to court disaster and produce confusion rather than edification. There is much to be said for the older ideas of separating " herbaceous plants" from ''trees and shrubs," and for mak- ing an independent arrangement of the two classes, mainly on the ground of cultural requirements. The natural system in plant houses, again, is almost cer- tainly doomed to failure, and an arrangement on geographical or ecological lines must perforce be; adopted. How instructive such an arrangement may be is shown by an arrangement of plants from alpine regions or by a collec- tion of xerophytes representative of some particular desert area of the globe. Plant physiology affords another basis for plant arrange- ment and perhaps is fruitful of greater educational value than almost any other system. It has the further advantage that it lends itself to adoption in the smaller garden where a com- plete conspectus of the vegetable kingdom is an impossibility. In some botanic gardens on the Continent, particularly at Berlin, and to a smaller extent at Geneva and elsewhere, the flora of mountain regions is arranged with an attempt at actual verisimilitude as to soil conditions and altitudinal dis- tribution of the zones of vegetation. The idea is an excellent one, but its realization is liable to be far from perfect since the limiting factors of altitude and climate are absent and the plants of the mountain tops, deprived of their natural restric- tions, tend to usurp more than their proper share of avail- able space. In whatever manner the main garden may be arranged, there should always be special portions set apart for certain well-marked plant types, such as alpine and rock plants, sue- 1915] HILL BOTANIC GARDENS 221 culents, bulbous plants, halophytes, bog and water plants, and the like, and if possible there should also be a definite economic and medicinal garden. Plant houses should also be set apart for economic plants where such as are of definite medical and economic values may be studied in connection with their products displayed in the museums. The exact determination of plants of economic value, es- pecially in connection with the vegetation of the tropics, is a matter of such importance that the necessity of a well- furnished herbarium and museum, in connection with a botanic garden of any pretension, needs no demonstration. With the aid of the herbarium, also the correct determination of all plants cultivated in a botanic garden should be ensured. Just as necessary for the complete botanical establishment is the possession of a laboratory both for the examination and analysis of plants, and also for the study of such problems in mycology, plant physiology, plant hybridization, etc., as can be studied nowhere at greater advantage than in a botanic garden. A somewhat unexpected exhibition in a botanic garden is an arrangement of fossil plants in the open, such as may be seen in the Breslau Botanic Garden, 1 where the coal measure series of strata have been built up and characteristic fossil plants have been arranged to form a kind of fossil rock- garden. Such an exhibition as this in close connection with the collection of living plants, is probably of greater educa- tional value than a similar display would be within the four walls of a museum and may be assumed to justify its forma- tion. How numerous are the possibilities of arrangement in the modern botanic garden has been fully realized by the en- lightened botanists of the present day. The difficulty, how- ever, which is being somewhat acutely felt in many institu- tions, is that of lack of space, not only for the vast numbers of new plants being introduced to cultivation — particularly from China — but also for new and important developments 1 Goppert, H. R. Der Konigliche Garten der Universitat Breslau, Fiihrer. 1875. [Vol. 2 222 ANNALS OF THE MISSOURI BOTANICAL GARDEN made necessary by the progress of the science of botany both for teaching purposes and for research. Experiments in plant breeding, for instance, which are a legitimate development of botanic garden research, demand an amount of space which many gardens are unable to afford, and in the tropics in particular such work has had to be rele- gated to definite experiment stations. In England work of this character is being carried on mainly in connection with agricultural institutions and at the newly-founded John Innes Horticultural Institution at Merton, under the direction of Mr. Bateson, while in the United States such lines of inquiry are being pursued with laudatory vigor by the United States Department of Agriculture and by many other public and private institutions. Another function of botanic gardens of first importance is the opportunity they afford for the training of men; and in work of this character Kew has probably played a larger share than any other garden. From Kew, in the course of her long history, her sons have gone out either as collectors or gardeners to bring home plants of interest and of economic value, or to take charge of the botanical establishments in the British Colonies and Dependencies. A glance at the Kew roll will also show how many of her young men are helping to propagate the art and science of horticulture in the United States of America. With some of our larger institutions one of the most import- ant functions in the past has been the distribution of plants of economic importance. The distribution of cotton seed, in 1732, by Philip Miller from the Chelsea Garden to Georgia (the parent stock of upland cotton), the introduction of Para and other rubber plants, and of Cinchona from South America through the agency of Kew, of tea into India by the Calcutta Botanic Garden, may be cited as a few among in- numerable cases. There are those who have expressed the opinion that this function of botanic gardens is now obsolete, but it does not require much reflection to perceive how wide is the field of usefulness still open in the direction of the intro- duction and distribution of plants. 1915] HILL — BOTANIC GARDENS 223 Our smaller botanic gardens then may rest content with the attempt to develop their resources on lines best calculated to stimulate interest and promote sound learning, both as centers of education and of research, while it falls to the lot of the larger institutions to display as far as possible the com- plexity and variety of the vegetable kingdom. The latter, with their herbaria, museums, and laboratories, are respon- sible to the world for the correctness of the information they supply, since in cases of economic plants incorrect determina- tions or injudicious advice may involve incalculable harm to the planting community, whose interests they serve. The magnitude of this responsibility has been fully appre- ciated, and the results achieved amply serve to demonstrate the success which has attended the efforts of the distinguished botanists who have guided the destinies of our botanic gardens. "The people will tell of their wisdom and the congregation will shew forth their praise." Books and Papers Relating to Botanic Gardens 1. Amherst, Hon. Alicia. A history of gardening in England. London, 1896. 2. Britton, N. L. Botanical gardens. Bull. Torr. Bot. Club 23: 331-345. 1896. Also in N. Y. Bot. Gard., Bull. 1 : 62-77. 1897. 3. De Candolle, A. P. Notice abbrgg6e de l'histoire et radministration des jardins botaniques. Diet. d. Sci. Nat. 24:165-181. 1822. (Unfortunately this account has not been seen.) 4. Holmes, E. M. Horticulture in relation to medicine. Roy. Hort. Soc., Jour. 31:42-61. 1906. 5. Johnson, G. W. A history of English gardening. London, 1829. 6. Kerner von Marilaun, Anton. Die botanischen Garten, ihre Aufgabe in der Vergangenheit, Gegenwart und Zukunft. Innsbruck, 1874. 7. Maiden, J. H. Functions of a botanic garden, etc. Roy. Soc. N. S. Wales, Jour, and Proc. 46: 1-73. 1912. [See pp. 49-73.] 8. Philippi, F. Los jardines botanicos. Santiago de Chile, 1878. 9. Pulteney, R. Sketches of the progress of botany in England. 2 vols. London, 1790. 224 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2, 1915] Explanation of Plate plate 4 Padua Botanic Garden. Photograph of plate in de Visiani's 'Dell' origine ed anzianita dell' orto botanico di Padova.' Padua, 183ft. (See p. 191.) Ann. Mo. Bot. Gard . Vol. 2, 1915 Plate 4 a r r 1 o > > z •"3' 3 COCKAYNE, BOSTON [Vol. 2, 1915] 226 ANNALS OF THE MISSOURI BOTANICAL GARDEN Explanation of Plate PLATE 5 Pisa Botanic Garden. Photograph of plate in M. A. Tilli's 'Catalogus Plai Pisani.' Florence, 1723. (For explanation see p. 192.) Ann. Mo. Bot. Gard., Vol. 2, 1915 Plate 5 roducctiu h i\iui Vitani H ■> iT> I / V *--v ■-> r\: ' ' • I \ ; I x ■- •-*! t I * «1 * V J •" u J ■ V ' "' V s - 1 U « -i I **mt?t .■ ^.v >T y 3 .\j ■ 3 ...'MS .j .vj: 1 At J j i >\*»: •^^ h .if- ■;/ I- jfi ~L. \ \ vj « — ^™ , i' L < . V* U «i I > rfc * *mi\ ii -», i ILLia. L 1 L i 1 >i ? < ■ ! ^ • '« ' r* - * 1 rt '• » j * V, ■ ■ gwJJH i , "i ""V* -\* -> - ill -\ J ... M «.T_ • tf «•■ to**.' - ^ 2 * j ■ _- m *■' v * « -i - v J » ' - J J J 1 - J W *_i •j ki w >> '*J ',31 i-? is « - J. a tttV ? 5* J , ) T < ; V 7^ 7 /' r \ is & -^fl J> '»' r/4 P(» Seal a uf'1,1 nim .wiri/m Fl o re ntina rum HILL— BOTANIC GARDENS .*i >»tj//, ^u^ COCKAYNE, BOSTON [Vol. 2, 1915] 228 ANNALS OF THE MISSOURI BOTANICAL GARDEN Explanation of Plate PLATE 6 Photograph of title page of Gerard's 'Herball.' 1597. (See p. 196.) Ann. Mo. Bot. Gard., Vol. 2, 1915 Plate 6 HILL— BOTANIC GARDENS COCKAYNE, BOSTON [Vol. 2, 1915] 230 ANNALS OF THE MISSOURI BOTANICAL GARDEN Explanation of Plate PLATE 7 Photograph of title page of Parkinson's 'Paradisi in sole Paradisus Terrestris.' 1656. [2nd ed.] (See p. 197.) Ann. Mo. Bot. Gard., Vol. 2, 1915 Plate 7 w MM ^ *■■•» A &** £#l ^ ^< ^ O l\* J k. w r >&* *••* *;v» v <:>* ►X 1 KT V4N V. \ r* X **T * ^N f##. " Jl *"^« ^ •^ 1 # t- < r V>~ -^ ^ _/ PARADISf*"IN SOLE Patadifus Tcrre^ms. &ry&f% ayrc Witt vermiit i9 Be nourfeS V£l *ehar£ of cSCJorit of JruiW** m(J ^rtt% n*C JfiruS&CS Jit ^for our \antf tot. i>i . i HILL— BOTANIC GARDENS COCKAYNE, BOSTON [Vol. 2, 1915] 232 ANNALS OF THE MISSOURI BOTANICAL GARDEN Explanation of Plate PLATE 8 The Oxford Botanic Garden, founded 1621. Reproduced from Log- gan's plan of the Garden in 1675. (See p. 197.) Ann. Mo. Bot. Gard., Vol. 2, 1915 Plate 8 South Elevation of the Conservatory O J . /V TV East Bridge HILL— BOTANIC GARDENS COCKAYNE, BOSTON [Vol. 2, 1915] 234 ANNALS OF THE MISSOURI BOTANICAL GARDEN Explanation of Plate PLATE 9 Royal Botanic Gardens, Kew, showing dates and extent of successive additions to the area open to the public and site of the original Botanic Garden of 1760. Photograph of plan in W. J. Bean's 'The Royal Botanic Gardens. Kew/ London, 1908. (See p. 206.) — Pub- lished by permission of Cassell & Co., Ltd, London, England. Ann. Mo. Bot. Gard., Vol. 2. 1915 Plate 9 Site of Batik cf Brentford AJDL1642 Site of Bidmmokd v DEER PARK HILL— BOTANIC GARDENS COCKAYNE, BOSTON [Vol. 2, 1915] 236 ANNALS OF THE MISSOURI BOTANICAL GARDEN Explanation of Plate plate 10 The Herbaceous Ground, Royal Botanic Gardens, Kew, showing bedi arranged according to the natural orders. Ann. Mo. Bot. Gard., Vol. 2, 1915 Plate 10 M r I o > z > Z GO COCKAYNE, HOSTON [Vol. 2, 1915] 238 ANNALS OF THE MISSOUKI BOTANICAL GARDEN Explanation of Plate plate n The Rhododendron Dell, Royal Botanic Gardens, Kew Ann. Mo. Bot. Gard., Vol. 2, 1915 Plate 11 a r I o > > z 73 COCKAYNE, BOSTON [Vol. 2, 19131 240 ANNALS OF THE MISSOURI BOTANICAL GARDEN Explanation of Plate plate 12 The Lake, Royal Botanic (lardons, Kew. Ann. Mo. Bot. Gard., Vol. 2, 1915 Plate 12 HILL— BOTANIC GARDENS COCKAYNE, BOSTON RECENT INVESTIGATIONS ON THE PROTOPLASM OF PLANT CELLS AND ITS COLLOIDAL PROPERTIES FREDERICK CZAPEK Pflanzenphysiologisches Institut der K. K. Deutschen Universitdt, Prague, Austria I have the honor of publicly congratulating the Representa- tives of the Missouri Botanical Garden upon the Twenty-fifth Anniversary of Henry Shaw's magnificent foundation, — the unique memorial of a magnanimous citizen of this great metropolis. I shall endeavor to show to the members of this splendid assembly how plant physiologists at present attempt to reach a satisfactory understanding of the wonderful mechanism which in never-ceasing variation is unfolded to us in myriads of phenomena characteristic of nutrition, reproduction, adap- tation, growth, and stimulation, in the lower as well as in the higher plant organisms. Wherever science is following these various processes to their mysteriously hidden roots, the physiologist has to face the complex problems associated with the living content, the so-called protoplasm of the plant cell. Without this singular matter plant cells are mere dead bodies able neither to grow, to take up food, nor to assimilate their nutriment. It was not until 1841 that Hugo von Mohl, the well-known botanist of Tubingen, discovered the important fact that all phenomena in cell life are strictly confined to the thin layer of slimy material which clothes the inside of each growing and living plant cell. He stated that this protoplasmic slime was stained deeply yellow by means of iodine, and he expressed the opinion that protein substances in particular were the con- stituents of this living material, from which all other parts and organs of the cell were believed to take their origin. We shall not be surprised to learn that biologists felt in- clined to suppose that the protoplasm might contain some Ann. Mo. Bot. Gard., Vol. 2, 1915 (241) [VOL. 2 242 ANNALS OF THE MISSOURI BOTANICAL GARDEN peculiar and highly complex proteins constituting the living matter in the proper meaning of the word, whose chemical qualities we should have to make responsible for the whole complex of life phenomena. Therefore, it appear* m! a most attractive problem to subject protoplasm to a thorough chemical investigation. The names of Reinke and Rodewald are connected with this work. These two botanists, in 1880, then in Gottingen, analyzed the protoplasmic mass, the so- called plasmodium, of Fuligo septica, a common species of the Myxomycetes. The result was that a part, about three- quarters, of the material was recognized to belong to the pro- tein group in the widest sense; while 25 per cent was a mix- ture of diverse carbohydrates, fatty bodies, organic acids, and inorganic materials. No evidence of the presence of any peculiar protoplasmic substances was found. Reinke, there- fore, laid emphasis on the point that protoplasm could not be regarded as a single chemical body of peculiar qualities, but that it should be considered as a mixture of various sub- stances, of which not even one was unknown to the chemists. The consequence of this view was that Reinke inclined to the hypothesis that the peculiarities of protoplasm were not due to its chemical nature but rather to its peculiar structure. The stuff-hypothesis had to be replaced by a structure-theory of protoplasm. At present, however, we can scarcely accept all conclusions drawn by Reinke from his famous analysis of protoplasm. Reinke thought that all the vital properties of living proto- plasm were destroyed when cells were killed, in the same way as the mechanism of a watch is destroyed by grinding it down in a mortar. The chemical substances, however, may remain unchanged while the mechanism is forever destroyed. The first experiments which proved that Reinke 's simile is not quite an exact one were obtained from studies on the various enzyme effects which continue in a mass of finely comminuted tissue. Among those effects we know a series of processes which undoubtedly belong to the complex of vital metabolism, — as, for example, to those of respiration and digestion. And these effects may be followed for weeks and for months after 1915] CZAPEK — PROTOPLASM AND ITS COLLOIDAL PROPERTIES 243 trituration of the cells, if precaution is taken to prevent change in the material by bacterial action. But the essential difference between such autodigestion and the life-process consists in the fact that the first is not ruled by the laws of correlation and regulation, which are so peculiar to life pro- cesses. Nevertheless, we cannot say that the whole of the life-mechanism is destroyed by grinding down living organs. At least a part of it cannot immediately be transformed by this type of disintegration. From this we may draw the con- clusion that there are certain chemical substances present in protoplasm which are responsible for certain activities of the living tissue. Such substances are the enzymes, which are entirely unknown in inanimate nature, and absolutely dis- tinctive of cell protoplasm. Further, we cannot suppress some scruple that in Reinke's analysis there were examined not the original protein-bodies of protoplasm, but only substances artificially produced during the treatment of the original material. Our chief objection against the "Engine-Theory" of proto- plasm is that no mechanism has hitherto been known which may be destroyed by heat as easily as is protoplasm, whilst on the other hand one cannot immediately and entirely destroy it merely by pounding to an impalpable pulp. Besides this, recent investigations on the proteids of animal organs — in which great care was taken to dry the pulp quickly at a tem- perature as low as possible — have shown that there really exist highly compounded protein bodies of hitherto unknown constitution which have to be considered as real constituents of protoplasm. Can such discoveries in some way explain the vital prop- erties of the cell? It seems as if we may not understand the wonderfully accurate working-together of all organs in cells without supposing trans-microscopical structural qualities; but we need not assume any mysterious new forces or struc- tures. Most of the well-known characteristics of protoplasm can be understood by considering further the colloidal state of the constituents of the cells. [Vol. 2 244 ANNALS OF THE MISSOURI BOTANICAL GARDEN The first naturalist who turned his attention to the great importance of colloidal substances in cells was Biitschli, the zoologist of Heidelberg. A great number of his admirable papers deals with the microscopical features of cell plasma, which he described as a framework of jelly-like substances containing interstices, or meshes filled with fluid substances. Biitschli emphasized the view that the foam structure de- scribed by him is not peculiar to living matter, because a mix- ture of oil and gelatin solution shows the same microscopical structure which he attributed to protoplasm and to all colloids. But later on it became more and more probable that such a foam structure in protoplasm indicates nothing more than certain gross features which are by no means identical with the real colloidal structure of plasmatic constituents. Not even in gels, or solid colloids, apparently, is the foam structure a dominant characteristic. Zsigmondy's recent work on gela- tinous structure clearly showed that while forming the gel the colloidal particles, which are distinctly visible in the ultra- microscope, do not arrange themselves in a network, but settle quite irregularly ; so that we cannot assume that meshes are formed in the precipitation of colloids. On the other hand, biologists of rank, as Lepeschkin, after a careful study of the microscopical structure and the physical properties of protoplasm, have arrived at the conclusion that we should not regard it as a foamy mass, or jelly-like substance, but rather as a liquid colloid with the characteristics of protein sols of certain higher concentrations. We can easily confirm the observation that protoplasm, examined by means of the highest power of the microscope, often appears merely as a homogeneous liquid, or transparent mass, sometimes mod- erately turbid from the presence of small distinct drops or corpuscules which are collectively known under the name of ^microsomata." Even though we do not accept Biitschli 's idea with respect to specific structure, we fully share his more general point of view that living protoplasm owes its peculiar activities to colloidal qualities. And this represents our attitude to-day towards protoplasmic investigation. 1915] CZAPEK — PROTOPLASM AND ITS COLLOIDAL PROPERTIES 245 The chemistry of colloids is not a descriptive science. To the utmost extent it has to use experimental physical methods. So we cannot advance in knowledge of protoplasm by mere microscopical observation, but mainly by experimental investi- gation. A long time even before colloidal chemistry became domin- ant as the basis for the physiology of protoplasm, a memorable epoch in plant physiology had opened, developing from the ingenious work of Pfeffer and De Vries on the osmotic prop- erties of living cells. These investigations unveiled the fundamental fact that living protoplasm alone is in posses- sion of those peculiar properties of permeability which are responsible for the whole complex of nutrition. Dead proto- plasm behaves quite differently. Since, however, differences in respect of the penetration of different solutions can be detected to a certain extent in colloidal membranes, it be- came probable that the so-called semipermeability of living protoplasm is a colloidal phenomenon, due to the constituent colloids in living protoplasm; whilst after the death of the cells the coagulation of these colloids completely changes the peculiar permeability of the protoplasmic layer. It was, however, Ernest Overton, in 1899, then at Zurich, who acquired the merit of placing colloidal chemistry in fundamental relation to the phenomena of diosmosis in living cells. The well-known theory of Overton consists in the hypothesis that fatty substances play an important role as constituent elements in the protoplasmic matrix. It is due to such substances, generally comprised under "lipoid bodies," that living cells show quite distinctive diosmotic qualities. Overton's hypothesis is founded upon the fact that only those substances which readily dissolve in fatty oils are easily diffus- ible in living cells; whilst all substances which are insoluble in oily media, as sugar or mineral salts, easily produce plas- molysis, because they penetrate into cells only very slowly. The leading physical idea in this theory was the so-called "Partition-Rule" of Berthelot and Jungfleisch. This law states the fact that there exists a constant relation between the Quantities of a certain solute dissolved in two immiscible 246 ANNALS OK THE MISSOURI BOTANICAL GARDEN [Vol. 2 solvents. Overton considered the endosmosis of dissolved substances into living cells as merely a question of solubility. It is known how fertile this idea has proved in physiology, particularly in the phenomenon of narcosis, where it is still the leading hypothesis in animal physiology. But recently experimental work, including my own, has shown that it is scarcely quite correct to consider the endos- mosis of solutions into living cells as a typical solution phenomenon. According to Loewe even the partition of methylene-blue or of chloroform between oil and water cannot readily be explained by means of the principle of Henry and Berthelot. Bather, the oily solution of such substances is not a true solution, but only a colloidal solution; so it is not ruled by the laws of osmotic pressure, but by the laws of adsorption. A striking fact was discovered by Traube and by myself in studying the effects of alcohols and other capillary-active substances on living cells. Their injurious action clearly and exclusively depends upon the relative capillary activity. Every one of these substances kills the cells at a concentration corresponding exactly to a certain value of surface tension. The main importance of this observation consists in the evi- dence that in narcotic effects capillary phenomena must be a dominant factor. This cannot be interpreted by the supposi- tion that the entrance of narcotics into cells is due to true solution phenomena. The observed capillary effects distinctly show that the factor of real moment is to be found in altera- tions of contact-surface ; but such surface-phenomena are met with only in colloids and in their adsorption. A prominent feature of our experiments involves the fact that cells of higher plants are constantly killed by concentra- tions of narcotics such that the capillary activity reaches about two-thirds of the surface tension of pure water in contact with air. It is remarkable that saturated and neutral emulsions of triolein or other typical fats always show approximately the same surface tension value. This result I tried to explain by means of the hypothesis enunciated in the following sentences: Alcohol and other narcotics are taken up by ad- 1915] CZAPEK PROTOPLASM AND ITS COLLOIDAL PROPERTIES 247 sorption into living protoplasm. According to the theorem of Willard Gibbs the surface in liquid systems which consist of different fluids and contain some capillary-active sub- stances is always occupied by those substances which show the greatest reduction in the surface tension of the medium. If subsequently another substance with greater capillary activity is added to the system it displaces all other substances from the surface. Narcotics may displace certain plasmic substances in an analogous way, provided that the surface tension of the concentration applied is just a little lower than the surface tension of the plasmatic substances referred to. The fact that the fatal narcotic pressure value coincides with the maximum surface tension in fat emulsions may be ex- plained by the hypothesis that fatal effects of alcohols on living cells consist in destroying the emulsion structure of protoplasm, by displacing some fatty substances. So our experiments to a certain extent uphold the view that the surface layer of protoplasm really contains fat, and thus far is in accordance with Overton's hypothesis. In the course of time the lipoid-theory of Overton has met with sharp criticism. Among other renowned physiologists, Ruhland strongly denied the presence of fatty bodies in the plasmatic membrane of plant cells. On the other hand, we are aware that animal physiologists, such as Fiihner, Hober, and Vernon still firmly adhere to the old lipoid-theory. However, since according to Overton sugars and mineral nutrient salts are believed to penetrate only poorly into the living cell, it is obvious that Overton's hypothesis stands in direct contrast to the common experiences in respect to plant nutrition. The substances referred to are materials which the cells have to take up as among their most important nutrients. Nevertheless, there have been developed some sup- plementary theories which permit us to lessen the difficulties of the lipoid-theory, for example, that of Nathansohn, accord- ing to which the lipoid membrane of protoplasm is not a con- tinuous film of fat, but a kind of mosaic of fat and protein which is able to permit the penetration of both fat-soluble substances and mineral salts. [Vol. 2 248 ANNALS OF THE MISSOURI BOTANICAL GARDEN Buhland's experiments especially were not at all favorable to the lipoid-hypothesis. They show decidedly the error of the opinion that only those aniline dyes penetrate into living cells which are soluble in oil. Many aniline dyes have been found which are easily taken up by cell protoplasm in spite of their insolubility in fat, while other coloring matters which easily dissolve in fat do not penetrate at all through the living plasmatic layer. Ruhland, as well as Kiister, drew from such experiments the convincing conclusion that substances readily soluble in lipoids may not always be readily taken up by the living cells. But in other respects it seems as if Ruhland had gone too far when he denied that protoplasm possesses any fat content. He emphasized that he never could detect any microscopical trace of plasmatic substances which may be stained by means of such aniline dyes as are readily stored by fat. Since our own experiments seem to be in some accord with the view that fatty matter really is present in protoplasm, I wanted to compare some chemical systems which are entirely free from fat with protoplasm in respect to its behavior toward alcohols. It could be taken as a proof of the view that protoplasm does not contain fatty bodies, if there were noticed no difference between the effects of alcohols on the physical properties of such systems and on protoplasm. The investi- gations of Mr. Geo. H. Chapman in our laboratory were begun in order to examine the influence of different narcotics on enzymes. Surprisingly, the results were opposed to the above- mentioned view of similar action with respect to these systems. This work clearly showed that the capillarity- rule which is so distinctive of the effects of narcotics on living protoplasm does not apply to the effects of narcotics on enzymes. While the deleterious influence of methyl, ethyl, and propyl alcohol gradually increases with the molecular weight of these homol- ogous substances, the higher members such as butyl and amyl alcohol act considerably less on enzymes, and both heptyl and octyl alcohol have practically no weakening influence on these ferments. In respect to their coagulation by diluted alcohol protein solutions show relations corresponding to 1915] CZAPEK — PROTOPLASM AND ITS COLLOIDAL PROPERTIES 249 those just discussed. In consequence of this result we can hardly explain the effects of narcotics on protoplasm by the view that only plasmatic protein bodies are influenced by such toxic agents. Besides this, for the coagulation of protein bodies there is required not less than five mols of ethyl alcohol while a little more than two mols is sufficient to kill living protoplasm. Therefore, some other substances in protoplasm besides the protein bodies must be affected by the alcohols, and these substances must differ from the latter in their physical properties. So it seems that the view ac- cording to which the plasmatic membrane is constructed ex- clusively of hydrocolloids, viz., proteins, as Ruhland believes, cannot be considered to be quite satisfactory. Our attention must be directed anew to the possibility that some lipoids play the part of important constituents of the protoplasmic mem- brane. On the other hand, I have to state that several lines of ex- perimental work have led us to the conclusion that the endos- mose of solutions into living cells never does take place by way of plasma lipoids, but only through hydrocolloidal con- stituents of the cell plasma. The work of Mr. Krehan, which dealt with the influence of highly diluted hydrocyanic acid on plant cells, distinctly showed that in the presence of this agent the permeability of cells to certain salts, such as sulphates, and to sugar, is raised, so that the threshold of plasmolysis for these substances is raised. When the effects of different salts on plasmolysis were compared it became manifest that just those salts causing the greatest rise of the plasmolytic limit, are those which were strongly adsorbed, and which display a most marked effect on the precipitation or coagulation of albumen. Such salts are sulphates, citrates, tartrates — by their anionic effects, and the salts of am- monium, calcium, and magnesium — by their cationic effects. These phenomena are only to be understood upon the supposi- tion that hydrocolloids are the media through which different substances must pass when taken up by the living cell plasma. There has been discovered not the faintest indication that [Vol. 2 250 ANNALS OF THE MISSOURI BOTANICAL GARDEN lipocolloids can play an important part in endosmose, as Overton originally suggested. If there really are plasmatic lipoids present, they probably have no significance as the path of nutrient substances into cells. But, on the other hand, lipoids certainly participate in narcotic effects, because the more soluble is this narcotic in fat the more of the narcotic substance is stored by the plas- matic substances. Consequently, the higher members of the series of alcohols are more injurious for cells than the lower, because the lipoid constituents of protoplasm become satur- ated with the narcotic and can discharge these narcotics only slowly. So the protoplasm succumbs to the influence of the narcotic agent. On this point I share the opinion of Boeseken and Waterman. The capillarity-rule can scarcely be explained otherwise than by the hypothesis that lipoids are present in the surface layer of protoplasm. So we are forced to continue our work as an exploration designed to determine if lipocolloids are present in protoplasm. A plan was devised and a decision was sought in the following manner: Emulsions of pure trio- lein or of olive-oil were prepared which had about the same surface tension value as have solutions injurious to proto- plasm. To a series of snmples arranged from such a fat emulsion alcohol in gradually increasing amount was added. The question now was whether there were effects produced on the emulsion in some way comparable to the action of alcohol on cells. Cell plasma contains also protein bodies and mineral salts. So our model of emulsion had to be compounded by adding a solution of mineral salts, as a physiologically balanced mixture, and by adding also albumen solution. The mineral salts were added as in the Van't Hol'f mixture in 0.1 molar concentration. An alkali is indispensable, so that 0.1 mol of sodium carbonate was used in order to produce a fine and stable emulsion upon shaking the mixture with oil. The results were in brief the following : When a fat emulsion from olive oil was prepared by mixing only oil, water, and sodium carbonate, the decomposing effect of alcohol on the emulsion was noticed at a concentration of 3 mols, i. e., about 15 per 1915] CZAPEK PROTOPLASM AND ITS COLLOIDAL PROPERTIES 251 cent. When concentrations higher than this were used then the emulsion, examined capillarimetrically, did not differ from a mixture of pure alcohol and water of the same concen- tration (but without oil). Then we added to the emulsion Van't Hoff's solution 0.1 mol instead of water. The decompo- sition of the emulsion by ethyl alcohol was now observed at 2 mols, i. e., about 10-11 per cent. This is just the concentra- tion of alcohol which kills cells of the higher plants. The addition of sodium chloride 0.1 mol instead of Van't Hoff's liquid showed the critical concentration of alcohol to be 3 mols, about the same concentration as in the absence of mineral salts. On the other hand, the addition of magnesium chloride induced the fatal effect of alcohol at 1 mol, much lower than in living cells. Magnesium sulphate showed the same effect as magnesium chloride, and the sulphate of sodium the same as the chloride. Therefore, it does not seem probable that the differing solubility in alcohol is responsible for the various effects of the salts. One may endeavor to explain these phenomena in the following way: Emulsions are only stable when the droplets of the emulsified fat remain suspended in a soap solution of approximate concentration. Substances which alter the limiting surface between the soap solution and the suspended oil must prove fatal as soon as their capillary activity surpasses the capillary effect of the soap solution. Bivalent cations, such as Mg and Ca, which form insoluble salts with fatty acids, lower the concentration of soap, so that alcohol must exhibit a decomposing action on the emulsion, even in lower concentrations. From such experiments it seems as if the critical concen- tration of alcohol for living cells would not be so sharply determined by proteins contained in protoplasm as by the mineral salt and the lipoid constituents of the protoplasm. Since we suppose that the various mineral salts in protoplasm are present in about the same concentration as they are found in sea water, or as they are mixed together in Van't Hoff's solution, we have to face the question whether the destructive effect of alcohol on living cell plasma consists in some decom- position of colloidal fat emulsoids in protoplasm. [Vol. 2, 1915] 252 ANNALS OF THE MISSOURI BOTANICAL GARDEN That protein bodies are not primarily affected by alcohol and other narcotics seems to be sufficiently proved by the fact that ethyl alcohol coagulates protein solution at a concentra- tion not lower than 5 mols, and that while the higher alcohols show fatal effects on living cells, they do not produce any protein coagulation. So we are brought, I think, by several facts to the conclu- sion that living protoplasm must be considered as a colloidal emulsion of lipoids in hydrocolloidal media, the latter con- taining proteins and mineral salts. For the endosmotic pas- sage of dissolved substances the fatty constituents of proto- plasm have no significance. The narcosis, however, and the deleterious effects of alcohols clearly show how lipoids, more than the protein constituents of the surface layer of proto- plasm, participate in such phenomena. The more we advance in the disclosure of the details regarding colloidal mixtures and structures in living protoplasm, the more indispensable it is to be reserved when applying the new results to the var- ious problems to which an approach is so tempting to the physiologist. Many may feel inclined to be disappointed when they ob- serve how much time and mental energy are needed to study only so small a question as that about the presence of fat in protoplasm. But now after some years' work on this sub- ject it may be seen how important a part is to be attributed even to the combination of mineral salts contained in the plasma colloids. And so we may hope that in the progress of research new and unexpected paths may become visible and open to the indefatigable investigator. Further, we shall not be discouraged if when after long and patient work some results and ideas are won which subsequently are proved untenable. We are all common soldiers in the great battle for truth in science, and we know that few will attain the happi- ness of planting the flag of victory upon the battlements of the conquered fortress. THE EXPERIMENTAL MODIFICATION OF GERM-PLASM D. T. MACDOUGAL i The doctrine of an inviolable germ-plasm has formed the foundation of many imposing edifices in biological thought, and facilitated many advances in genetics and heredity during the last two decades. The authors who have rigidly adhered to the principles of the hypothesis and reasoned from its tenets have exposed many fallacies which have been offered in ex- planation of problems in evolution. This prevalence of theoretical considerations over mistaken experiences has laid the foundation for an unreasoning devo- tion to the idea of an independent germ-plasm, carrying agents which may not be seen, measured, or tested in any practicable manner, and which might consequently be termed "idealo- plasm" with attributes approaching the supra-physical. The desperate straits of those who voluntarily consign them- selves to the bondage of such a conception is well exemplified by the group of writers who subscribe to the conclusion that all evolutionary movement is due simply to recombination and re- arrangement of qualities or factors already present in the protoplasm. An additional illustration of the futile extremes to which this view may be pushed is to be found in the recent utterances of Bateson, who has arrived at the conclusion that evolution is mainly and essentially loss of inhibitors, and re- lease of activities previously latent or suppressed, an hypoth- esis which predicates premutation. If it be allowed that the non-appearance of a character is a direct loss of its determiner and that the appearance of a new feature is the loss of a retarder or inhibitor which held it in abeyance, then the answer to the question as to the method by which organisms have arrived at their present condition is obvious, but of a simplicity that is metaphysical instead of actual and hence of little value, even tentatively, as a frame- Ann. Mo. Bot. Gard., Vol. 2, 1915 (253) 254 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 work on which now concepts in biological science may be for- mulated. The group of problems with which we are endeavor- ing to make headway are in the domain of physiology and their solution may be reached only by experimentation, the re- sults of which are to be interpreted in terms of physico-chem- ical activities and their correlated functional manifestations in the living organism. That phylogenetic advance in the main lines of descent in the plant kingdom at least reflects, or harmonizes with, the ex- pectancies of somatic experience is tacitly admitted on all hands, but that the direct response of a shoot to the environ- ment, or conversely stated, that the impression on the soma made by environic agencies is communicated to successive gen- erations in a constant manner has not been demonstrated, although it seems fairly established that certain experiences of individual plants are reflected directly or indirectly to the next generation, and in lesser degree to the next or second generation. How are lasting or permanent changes brought about? Functional adequacy and architectural suitability present themselves on every hand, yet about all of our reliable evi- dence is against anything like a direct or functional adaptation becoming hereditary or continuously transmissible. Two methods of experimental attack on the problem are available. Species showing measurable features and of sim- ple genetic constitution may be taken from their habitual or known environment to other localities in which the climatic and soil characters may be calibrated and the response of the organism, somatically and hereditarily, determined. Hun- dreds of thousands of introductions and acclimatization opera- tions have been carried out in agriculture, horticulture, and especially in botanic gardens during the last century, yet neither the genetic constitution nor the response of the or- ganism has been followed by trained observers who compared the plants in their different habitats. The exposure of the organism to any climatic complex, of course, might affect the germ-plasm directly, and any departure detected in such ex- perimentation must be evaluated by controlled cultures under 1915] MACDOUGAL MODIFICATION OF GERM-PLASM 255 laboratory conditions in which both the nature of the reaction and the identity of the inciting agent may be found. The most notable series of experiments of this character which have as yet been carried out are those of Tower with the potato beetles. Over two hundred species of seed-plants selected for their suitability and promise of response have been taken into the series of cultures of the Department of Botanical Eesearch on mountain top, desert, and at the sea-shore, less than eighty of which have survived and about a score continue in all three locations. The most notable feature in the behavior of these plants put under stress in unaccustomed habitats consists in divergences in sexual reproduction and seed-formation. Con- jointly with this decrease of the sexual reproduction, vegeta- tive propagation assumes a greater importance. Shoots are variously affected. The measurement of these departures and their fate when the nth. generation is returned to the original habitat, or to a place in which the habital tension is changed, will be necessary to determine whether or not perma- nent impress on the species has been made. The second method would include all forms of experimenta- tion in which inciting agents would be applied directly to the reproductive bodies, in which case any deviation from the usual or typical would be more clearly attributable to changes in the germ-plasm. It is pertinent to call attention to the necessity for new viewpoints and new standards in the evaluation of any results which may be obtained in such manner. We are not likely to go far or progress easily into the region of the unknown if we attempt to interpret these effects too directly, with the idea that determiners, inhibitors, genes, etc., are ultimate or even penultimate units. In brief, the time has come for testing the performances of lineal series of organisms by methods in which attention will be centered upon the physico-chemical complex and an open eye will be kept for cleavage lines which may cut across directly or obliquely the limits of all of the arbitrary concepts of alternate inheritance. The house of the living thing is inclusive of walls, doors, roofs, windows, floors, [Vol. 2 256 ANNALS OF THE MISSOURI BOTANICAL GARDEN ceilings, rafters, and plumbing, but the materials used may be bricks, stones, metals, sand, lime, boards, glass, and paint. Our present needs lead us to experiments with these com- ponents rather than to trials of the possible combinations and inhibitions, possibilities and impossibilities of sets of builders ' blocks, no matter how complete or full these may be. Living material is a colloidal complex with its enmeshed re- actions highly fluctuant, its combinations unstable and its types of energy transformation multifold. It is concrete, however, and amenable to experimentation of many kinds. Its physical qualities and form undergo changes of phase which have some correspondence with the mechanism of mor- phogeny, reproduction, and heredity. Thus, for instance, in the higher plants the germinal protoplasm in the earlier stages of the individual is in the form of meristematic tracts made up of highly distended plasts in which absorption of water, hydra- tation, auxetic enlargement, and division of the separate ele- ments is very marked and rapid. Elements at the peripheries of these masses are separated which undergo differentiation and pass into the permanent tissues of the individual. These separating cells may be modified to an enormous extent by external agencies; thus conditions of aridity acting upon an individual may cause the tissues formed from its embryonic tracts to make such structures as to give the organs which they make up a xerophytic aspect. This final xerophytic or other character of the soma, how- ever, is in the permanent tissue, and the modifications which have resulted in its specialization ensued after the cells were pushed away from the meristem, and there seems to be no reflection of the final fixed qualities back to the embryonic tract, although there are many promising possibilities to be considered. Of these none are more interesting than the regenerative processes by which highly specialized cells reassume embryonic activity and reproduce members or indi- viduals vegetatively. Actual tests of the transmission and permanence of the specializations under these conditions have not yet been made with that exactitude which would allow any serious conclusion to be formulated. At certain stages of the 1915] MACDOUGAL MODIFICATION OF GERM-FLASM 257 ontogeny, generally much later in the plant than in the animal, and this is a matter which may be determined by the environic agencies, the germ-plasm or meristem tract undergoes such change of phase that instead of all of its separating elements passing into somatic cells a few become reproductive masses from which sexually specialized elements may be differenti- ated, and in which the number of chromosomes, the metabolic balance, degree of hydratation, auxetic energy and mechanism of division suggest physico-chemical conditions widely dif- ferent from those of somatic elements ; furthermore, the repro- ductive elements are highly individualized. The meristem in its myriad cells may at any moment present all of the phases of growth and differentiation. The egg nucleus or the fer- tilized egg, a single element of the plasma, may include the fate of the individual and its unending line of progress, and it may be affected in its entirety by agencies impinging upon it. The reaction of such specialized cells to external agencies would of course be different from those of the meristem tracts, which are made up of plasmatic units of the most generalized form. The experiments of Tower with the Leptinotarsae, which have been carried on under widely diverse conditions in southern tropical Mexico, in the arid semi-tropical climate of the Desert Laboratory, and under controlled conditions at the University of Chicago, furnish a great series of cultures of these beetles in which it is possible to demonstrate logically by exclusion and analysis that certain climatic features, notably moisture, may affect the germ-plasm, or the entire organism when the germ-plasm is in a certain stage, in such manner as to induce disturbances in hereditary lines. These experi- ments show the vulnerability of the germ-plasm. That the germ-plasm is directly responsive to the action of foreign substances which are introduced into the embryo-sac was demonstrated when (early in 1905) I was so fortunate as to hit upon an experimental method of treatment of the ovaries of seed-plants which resulted in the formation of em- bryos developing into individuals not entirely identical with the parental types. The essential feature of the discovery [Vol. 2 258 ANNALS OF THE MISSOURI BOTANICAL GARDEN consisted in the successful introduction of various substances into the neighborhood of the embryo-sacs at the time that fertilization was imminent, and when the first trials were made I had two main purposes in mind: first, to ascertain whether or not foreign substances could be introduced into ovaries in such manner as to affect the ovules with a minimum of trau- matic effects, so that the ovaries might reach maturity; and secondly, to ascertain whether or not such changes could be produced in an early stage of sexual specialization, before the development of the embryo-sac or after the union of the sexual elements in fertilization. - The first results were obtained with pure strains of Oeno- thera biennis and Raimannia odorata at the time mentioned, but the transfer of my activities from the New York Botan- ical Garden to the Desert Laboratory made it impossible to carry out cultures of the progeny or to repeat similar experi- ments upon this material. Meanwhile, Col. K. H. Firth, of the Royal Medical Corps of (Jreat Britain, duplicated 1 my general results with Raimannia and other plants in 1908, al- though the fact that I had previously done this work was unknown to him. New material was selected from the vicinity of the Desert Laboratory and the tests were begun anew in 1906. The diffi- culties to be overcome in such experiments are fully commen- surate with the importance of the problem upon which they bear. It is a necessary preliminary that the plants chosen for the operations should be an elementary strain, a matter which may need two or three years for determination, if not already known. Next, not all ovaries will withstand the shock and injury inflicted in the operations. The chances of ulti- mate success will be greatest in many-seeded ovaries in which the number, however, does not extend much beyond that of ovules which may be affected by a single operation, giving some opportunity for differentiation of effects and not entail- ing large cultures. Lastly it is advantageous to deal with perennial species which come quickly to maturity. This gives 1 Firth, R. H. Roy. Med. Corps, Jour. 16: 4D7-514. 1911. 1915] MACDOUGAL — MODIFICATION OF GERM-PLASM 259 the operator opportunity to preserve the original material alive and to have it for comparison with succeeding genera- tions. The numerous cacti in the vicinity of the Desert Laboratory lead them to be selected for some tests, and the mechanical conditions for operation which they offer are unexcelled. As much as 1 cc. of solution may be introduced into the ovary of an opuntia without traumatic effects, but as all are under suspicion as to their genetic complexity, and as they germi- nate and develop slowly, the investigator must wait the greater part of a decade to obtain decisive results. Striking depart- ures were obtained with Echinocereus Fendleri, a small cylin- drical form native to southern Arizona, and the changed characters grouped in one derivative have not been obtained in nature or in cultures of the original. This derivative has been obtained a second time. The species, however, presents such a complexity of characters that definite conclusions are difficult. Similar conditions were encountered in Penstemon Wrightii, about which an announcement was made in 1909. Some of these, however, furnished material from which the greatest sources of error might be eliminated. The search for suitable subjects for experimentation was continued and the results with Penstemon led to a closer ex- amination of other members of the Scrophulariaceae. Finally, an undescribed species of Scrophularia from the pine-forest area on the Santa Catalina Mountains in Arizona was brought into the environic series of the Laboratory of this Department in 1909. Eootstocks were taken to the Coastal Laboratory, and seeds were germinated at various localities. After hav- ing seen many hundreds of plants taken from various parts of its range and having followed them thoroughly two and three generations, it was found that the species is a simple one and not readily separable into elementary forms or strains. The only noticeable feature suggestive of complications was the fact that the broad-bladed nepionic leaf-forms are sometimes carried nearly to the summits of stems grown under certain conditions, giving the appearance of a robust race. [Vol. 2 260 ANNALS OF THE MISSOURI BOTANICAL GARDEN Another feature that received attention was the fact that branches formed in the closing part of the cycle of develop- ment of shoots bear leaves very much smaller than those aris- ing from the median part of the main stem during the first part of the season. The flowers borne on these branches are also much paler than those on the more robust branches. Peloric flowers sometimes appear near the apices of the in- florescences in this as well as in other species of the genus. It is to be noted also that the divisions of the corolla are variously and irregularly incised on individuals at times dur- ing the season, but these are not heritable and do not appear in any regular manner. This scrophularia appearing to offer some promise, several ovaries of a plant at Carmel were treated with solution of potassium iodide, one part in forty thousand, in July, 1911, and the ripened capsules were collected in September of that year. No record was made as to the time of day (see page 268) and nothing may therefore be said as to the possibilities of the action of the reagent on egg or pollen nuclei, singly, together, or after fertilization. No other species of Scro- phularia grew near the cultures at that time. The seeds were sown in suitable pans of screened soil, and in February three plantlets had survived. In May these were set in the open and their development followed. One formed a shoot fairly equivalent to the normal, finally producing flowers in which the anthocyans of the flowers were of a notice- ably deep hue. The two remaining plantlets were character- ized by a succulent aspect of the leaves, and by a lighter or color of the leaves and stems. Inflorescences were matured late in 1912, and the flowers on one of the derivatives, as they may be called, were so completely lacking in color as to be a cream-white, this derivative being designated as albida, while the other showed some marginal color and a rusty tinge, and was designated as rufida. Some disturbance of the relative velocities of development of the fibrovascular elements and mesophyll had taken place in both forms, so that the leaves were variously bowed and con- vexed and the two halves of the laminae were unequal and the ow 1915] MACDOUGAL — MODIFICATION OP GERM-PLASM 261 whole blade was more oblique in outline. The elongation of the lamina had been checked and the ratio of width to length of the leaves was greater than in the parental stock. If cor- respondent leaves of rufida and the originals were laid side by side it could be seen that the basal veins on the side away from which the tips were curved were different in the two cases, the derivative showing two strong veins in the place in which one lateral with a thin branch occurred in the original (fig. 1). The water relations of derivatives and normal were not identical, and when young shoots or branches developed Fig. 1. 0, branching lateral vein in parental 8 crophularia ; D, branching vein replaced by two laterals in leaf of modified 8 crophularia. under similar conditions were detached, those of the deriva- tives flagged and wilted much more quickly than those of the normal. The auxetic departures noted above also extended to the inflorescences, which in the original show a fairly regular basipetal development into thyrses. The derivatives, how- ever, exhibited a rather irregular maturation of clumps of buds and the thyrses were very irregular, not reaching the spread of the parental forms. The fragility of the leaves does not seem to extend to the flowers, which opened very slowly, and in some cases the distended corolla persisted for a few days. The amount of color in the corolla was largely a matter of illumination, but under equivalent circumstances the derivatives always showed less than the parental form. As noted above the color persists to some degree in the deriva- [Vol. 2 262 ANNALS OF THE MISSOURI BOTANICAL GARDEN tives along the margins of the uppermost lobes of the corolla, while that on the broad upper surface disappears. It is to be recalled that it is the color of this region which is variously disposed in other species of the genus. The corolla lobes were irregularly incised in the flowers of the first and second seasons of the Fi, as they have been seen to be in the original, but in the second generation of both derivatives cultivated at the Desert Laboratory this effect per- sists as a regular wedge-shaped incision of the lower lip only, and is not seen in every individual of both derivatives, although the seeds were from plants which may have been pollinated by the parental form. Seedlings from the original stock grown from seeds gath- ered on the Santa Catalina Mountains in Arizona were sowed early in 1910 at the Desert Laboratory and the plantlets pre- served on April 15 furnished the data : First pair of leaves smaller than in the derivative, being only 13-15.5mm. wide and 16-18mm. long, obscurely dentate with not more than two or three blunt teeth showing on each side. The petioles were 12-16mm. long. The third pair of leaves above the cotyledons, which probably were not quite mature, had petioles 20mm. long, and laminae 22-25x50-52mm. Mar- ginal stalked glands were so numerous that 15-20 appeared in the field of the microscope at one time, and these structures were very numerous on the petioles. It is to be noted that differences in the last-named feature between this original and the derivatives disappear in the adult, or on the leaves appear- ing in the later stages. Seeds from the original two derivatives matured at Carmel late in the summer of 1913 were sowed in the greenhouse at Tucson in November, 1913. But one plant of albida, the ex- tremest departure, survived, while four of rufida were secured. These, of course, represented the F2 of the departures. The measurements of rufida correspondent with those of the original are as follows : First three leaves deeply incised, five or six teeth on a side, abruptly pointed. Petioles 18-22mm. long, laminae 21-26mm. wide and 41-45mm. long. Mature leaves on sixth, seventh and eighth internodes, with petioles 1915] MACDOUGAL MODIFICATION OF GERM-PLASM 263 36-45mm., and laminae 36-56x85-100mm. Marginal glands showing 6-10 in field, few on the petioles. The single plantlet of albida bore leaves, the first pair of which were not deeply cut, the three or four teeth on each side being abruptly but sharply pointed, the petioles 15mm. long, and the laminae 24r-26x35-38mm. The leaves from the sixth, seventh and eighth internodes had petioles 30-40mm., and laminae 45-51x90-100mm. Not more than four stalked glands might be seen in the field at any one time. These trichomes were very sparsely distributed over the under surface of the petioles only. The greater relative width of these leaves was correlated with a greater angle of divergence of the lateral veins from the midrib, a feature which, as will be shown later, was to be observed in adult plants. The three plants representing the progeny of the treated individual were established in a row within a half meter of each other at Carmel in 1912. Irregular clusters of long thickened roots were formed, and these, as is customary with the species, bear buds and are a means of propagation of the plant. The three plants were taken up in November, 1913. While the main clumps could be identified, yet broken frag- ments of roots were preserved which could not be assigned to any one of the three, and although these were and are still pre- served they are not taken into account here. Albida was divided in May and June, 1914, and portions were sent to cooperators in New York, St. Louis and Chicago, but all failed to survive this unseasonable transplantation, so that at the present time this strain is represented by only two clumps, one of which is at the Desert Laboratory and the other at the Coastal Laboratory. The single plant of albida bloomed at Tucson early in the year, while the one at Carmel reached that stage too late to mature seeds. Rufida was divided into three clumps and reset in the garden at the Coastal Laboratory in November, 1913. The shoots from these began to open flowers in July, 1914, which corre- sponded in all essential particulars with those of the previous seasons except that they were more highly regular. Two were enclosed in small glass cages for protection and to insure [Vol. 2 264 ANNALS OF THE MISSOURI BOTANICAL GARDEN close pollination, a strong individual of the original being similarly enclosed for purposes of control. Conditions being favorable for a minute comp of these plants with the parental type, colored illustrations of flow and bud and diagram of structure were prepared. The inequality of the leaves was recorded by direct prints. The dimensional relations noted above The readiness with which the leaves flag was noted and in these organs, as well as in the stems, it was seen that rigidity is maintained by tur- gidity rather than by stiffness of the mechanical tissues. The development of the bast-fibers is less marked in the derivative, Fig. 2. Lower line shows outline of angle of stem of parent Scrophularia; upper line outline of same feature in derivative. and a similar deficiency of wood-formation is noted. A cor- respondent difference is apparent in the wings of the angles of the stems, which are thick with their sides parallel in the original, while in the derivative these decrease in thickness gradually toward the margin, with the effect in cross-section seen in fig. 2. The actual value or importance of these dif- ferences is not a matter of moment in the present connection. The chief interest lies in the fact that recognizable effects have been produced by the introduction of foreign substances into ovaries and that the differences shown by the first generation, Fi, are borne by the second generation, F 2 . The original ob- servations with the plant in which this was demonstrated 1915] MACDOUGAL — MODIFICATION OF GERM-PLASM 265 began in 1909, the treatments were made in 1911, and now first and second generations of the derivatives are alive, as well as the original stock. Much irrelevant comment and inconclusive experimentation has followed the original announcement of the discovery of the methods used in this work. The necessity for a careful genetic analysis of the material for treatment has already been noted, and it may be well to call attention to some of the features of operation which might appear simple, yet are not easily carried out. No better way has yet been found for in- troducing solutions into the region of the embryo-sac than by injection into ovaries with an all-glass syringe fitted with gold needles (14 karat). The wounding of the ovary produces abortion in some species, and in almost all treatments some of the ovules are crushed. This, however, is a matter of no mo- ment if some reached by the reagent survive and come to maturity. The extent and mode of diffusion of the reagent is in fact one of the most important features of the treatment, and the experimenter will do well to make control tests for the purpose of finding out whether or not there is some possibility of success. A test of the ovaries of Carnegiea previously described showed that the liquid was taken up by the placental vessels and conducted to a point near the egg cell in a very short time if the reagent were introduced into the ovaries of flowers fully open and mature. Operations made at an earlier stage re- sulted in the accumulation of the reagent in the inner walls of the locule, in the integument of the ovule and especially at the micropylar orifice. The pollen tube would be subject to the action of the accumulated substance in the micropyle and integument in this case. 1 It being my present intention to extend experimentation in the Scrophulariaceae, tests have been made with methylene blue in the ovaries of Penstemon Torreyi, the solution being one part of the dye to ten thousand of distilled water. 1 MacDougal, D. T. Alterations in heredity induced by ovarial treatments. Bot. Gaz. 51:241-256. 1911. 266 [Vol. 2 ANNALS OF THE MISSOURI BOTANICAL GARDEN Three hours later but little of the color could be found of the Next, five ovaries of Oenothera 3.21 —OK* Fig. 3. Diagram of flower of Scrophularia, showing mechanical features of ovarial treatment: s, sepals; c, corolla; g, nectar gland; p, placenta; st, style; ov, ovule; rec, receptacle; p, tip of hollow needle thrust through the ovarial wall and penetrating the placenta. The stippling shows the diffusion of a solution of methylene blue introduced by the needle. — Drawn by F. E. Lloyd. (a stable cruciate hybrid) were injected with a solution of one 1915] MACDOUGAL — MODIFICATION OF GERM-PLASM 267 part in a thousand. Fifteen to forty ovules had been touched by the color in young flowers not yet open. A much larger number had been colored in the ovaries of mature flowers. This solution was introduced into ovaries of the scrophularia under examination (fig. 3). Young ovaries in this plant showed very few ovules affected, none in a few cases. Older ovaries in which fertilization had probably taken place showed as many as 15-20 colored ovules. Probably only a small pro- portion of the ovules affected would have survived and de- veloped into viable seeds, so that many of the treated ovaries would have yielded nothing but normal seeds. This condition is to be taken into account by those who do not recognize the technical difficulties in the way of duplication of any particular treatment. The recent results of Churchman and Russell 1 in securing stimulation of the growth of animal tissues with methylene blue suggest that this substance might produce some effects on the embryo-sacs of plants, and also the advantage of using a reagent the diffusion and penetration of which are visible and obvious. It was desirable to use this dye in obtaining some knowledge of the probable action of other solutions in Scrophularia, so tests were made with this plant. A number of ovaries on a detached shoot in the laboratory were placed in a solution of one to a thousand at 9:30 a. m. Material was taken for ex- amination at suitable intervals. The placental walls and funicles were stained in part within a half hour. Two hours later the color had advanced well along the conducting tract in the funicular stalk. Five hours after treatment a notable amount of the dye had been carried clear to the embryo-sac, where it stained the nucellus and the antipodal region deeply. It is to be noted that the material was still alive and that this material if left attached to the plant would have developed some mature seeds in all proba- bility ( fig. 3 ) . 1 The effect of gentian violet on protozoa and on growing adult tissue. Soc. Exp. Biol, and Med., Proc. 2: 124. 1914. 268 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 Professor F. E. Lloyd, of McGill University, who kindly came to my aid in this matter, now made a brief study of the intra-vitam staining in the ovules of Scrophularia and found that the reagent accumulated throughout the embryo-sac in- clusive of the egg cell, demonstrating the possibility of the direct action of introduced solutions on the entire egg appa- ratus as well as upon the endosperm. The micropylar orifice was closed and was not stained in the ordinary treatments and took up only a small amount of the dye when laid separately in a solution of it. Professor Lloyd also showed me prepara- tions in which pollen tubes deeply stained had entered the micropyle and had elongated, reaching the egg. 1 These experi- ments made clear the immediate possibility of reagents reach- ing the egg apparatus through the funicle and of the staining of the pollen tube and nucleus in the cavity of the ovary before fertilization. It is also possible that the pollen tube might be affected by reagents which had accumulated in cells through which it penetrates to the egg nucleus (fig. 4). These facts would make it probable that treatments before pollination has taken place would affect the embryo-sac and its inclusions only, while introductions of solutions at a later stage would be likely to affect the pollen tubes and nuclei. These generalizations are to be taken to be applicable to Scro- phularia, and to species which present similar arrangements for reproduction. The egg in ovules in which the micropyle is open might be even more readily exposed to the action of a reagent, and if the ovule is porogamous the pollen tube would also inevitably be affected, and still many other combinations may be encountered which need not be enumerated at this time. It is of course to be understood also that not all of the ovules in any pistil are in equivalent stages of development at any given moment, and this applies also to the penetration by the pollen tubes. Pollination of Scrophularia takes place in the morning, and substances introduced before mid-forenoon 1 See Lloyd, F. E. The intra-vitam absorption of methylene blue in ovules of Scrophularia. Report of the department of botanical research for 1914. Carnegie Inst. Washington, Yearbook 13:77-81. 1914. 1915] MACDOUOAL — MODIFICATION OF GERM-PLASM 269 would be taken up and diffused through the tissues, especially through the funicle before the pollen tubes had reached the cavity of the ovary. Introductions timed to meet the elongat- mic- 'otsum Fig. 4. Diagram of longitudinal section of ovule of 8 crophularia : fun, funicle; chal, chalaza; ant, antipodal cells; tap, tapetum; end, endosperm; mic, micro- pyle. The shading shows the course of a solution of methylene blue diffusing through the funicle from the placenta (see fig. 3) and its selective fixation in the tapetum and nucellus. The solution finally reaches the ovum. ing pollen tubes would of course be more liable to affect the pollen nuclei, and a number of lots of seeds matured in ovaries [Vol. 2 270 ANNALS OF THE MISSOURI BOTANICAL GARDEN treated at various stages of development now await germina- tion and test. The differences between the two surviving derivatives of Scrophularia described in this paper may well be due to such differential action. It is to be seen that if egg or sperm were affected singly the resultant seed into which these elements might enter would be hybrid. Even if both were acted upon, it is by no means to be taken for granted that the effects in the two would be equivalent. The F2 of rufida was identical in the cultures described, while the F2 of albida presented some modifications, the status of which is not yet established, as both were open pollinated in the Fi. Very little informa- tion as to hybrids in Scrophularia is available. Goddijn and Goethart 1 report that S. Neesii Wirtg. X &> vernalis L. is a unified, stable, intermediate type and that the reciprocal is of a similar character. The behavior of the original stock, and the facts of fertiliza- tion, yield nothing suggestive of parthenogenesis, and the de- rivatives may be taken to be produced by a typical fertiliza- tion. No cytological examination has yet been made for the purpose of ascertaining possible differences induced in the chromosomes. This discussion may be fittingly brought to an end by a brief reconsideration of the salient ideas which have been touched upon. The point of view taken throughout all of the work which has been described is one in which the conception of a theoretical or idealized germ-plasm has been relegated to secondary position, and attention has been concentrated upon the concrete germ-plasm of the higher plants. This physical basis of heredity is seen to present two distinct phases. In one it takes the form of a meristem or embryonic tract of highly distended cells in which auxesis and division are both rapid and the elements which are separated from it pass by differentiations into the permanent tissues of the soma. En- vironic agencies affect only the development of the somatic cells which are being formed from the meristem, and the ex- 1 Ein kiinstlich erzeugtor Bastard Scrophularia Neesii Wirtg. X 8. vernalis L. Van's Rijks Herb., Mededeel. 1913 1 *: 1-9. 1913. 1915] MACDOUGAL — MODIFICATION OF GERM-PLASM 271 perience of these cells are not reflected back to the embryonic tract, so far as available facts may be considered. Sexually specialized reproductive elements with a reduced number of chromosomes are developed from the embryonic tracts in a late stage of the ontogeny, and these elements present a meta- bolic balance different from that of the meristem stage, the colloids having a greater density, and some of the energy transformations having altered velocities. The embryonic tract or meristem of a higher plant at any given moment includes an enormous number of primitive or initial cells and of separating elements in all stages of division, growth, and differentiation toward the specialized tissues which are derived from it. The tract as a whole could there- fore not react in a unified manner to any climatic or environic agency which would impinge upon the plant. Such forces, as a matter of fact, visibly affect only the manner in which the dif- ferentiation of the resting tissues takes place. The rejuven- escence of such differentiated cells might carry the effects into the organ or individual produced by the regeneration, but no test has yet been made of this matter, or of the transmission of such supposititious characters to a second sexually produced generation; neither has the proposal, that repeated or long continued exposure of the germ-plasm to any environic stimu- lus may result in the fixation of effects, been tested out. The continuation of introduced species in the mountain, desert, and coastal plantations of the Department of Botanical Research for the term of years during which any one person might con- duct such experiments, may not be taken as an adequate test of this phase of the matter, although these cultures are carried on for the express purpose of determining what permanent changes may be induced by the tension of unusual environic complexes. So far these have been confined to alterations in sexual and asexual reproductive procedure, and to alterations in structure and aspect of the shoot, while no tests have been made upon the fixity of the changes. Aberrant behavior of the chromosomes in certain determi- native or initial cells may possibly be responsible for bud- mutations or bud-variations, and theoreticallv it is conceivable [Vol. 2 272 ANNALS OK THE MISSOURI BOTANICAL (-AKDEN that special stimuli might be applied to such cells in a maimer that might bring about similar results. Practically, however, it would be enormously difficult to localize initial cells with sufficient certainty so as to give any slight chance of success. The second stage of germ-plasm in which it is in the form of sexually specialized elements oilers far more promising conditions for experimental modification of the genetic con- tent of the species which it represents. Solutions may be in- troduced into the ovaries in such manner as to affect the egg bearing the entire group of qualities of the species, and fur- thermore the direct action of such reagents may be ascertained to some extent. The present-day aspect of the mechanism of heredity is one which increases momentarily in complexity. The greater part of the researches in genetics during the last fifteen years has been devoted to the interaction of factors, determiners, in- hibitors, or qualities in the organism. If these conceptions may be taken to be the expression of the reactions of either chemical groupings or to rest upon a physico-chemical founda- tion of any kind, the reagents which have been used have not been of a selective character, but would affect practically the entire colloidal mass of the protoplast in some manner and to varying extent, neutralizing or coagulating proteins, and their general tendency would be to inhibit or check energy trans- formations. In the case of the iodine treatments the free ions from potassium iodide or the iodic acid formed would cause a neutralizing effect, as it does not seem from the results of Czapski and Adler 1 that this element would form any com- pound with the proteins. The experimenter is dealing with an actual physico-chemical complex of highly unstable compounds in which many types of energy transformation are occurring. Introduced sub- stances may slow down or inhibit some of these, and accelerate others or start new reactions. The morphological possibili- ties in any given strain of plants are somewhat limited, how- ever, and in this sense the direction of the departures is al- 1 Beitriige zura Chemismus der Jodwirkung. Biochem. Zeitachr. 65:117. 1914. 1915] MACDOUGAL — MODIFICATION OF GERM-PLASM 273 ready determined. This limitation of the possibilities of morphogenesis is the chief one in any expectancy of duplica- tion of results in successive treatments, outwardly mechanic- ally identical. The variables in any experimental setting are many, and the briefest consideration of the physical effects consequent upon the introduction of a foreign solution to the vicinity of the embryo-sac, reveals at once the lack of probability of exact repetitions in a mechanism so complex. The conditions are much different from those which would be presented if free floating eggs or sperms were immersed in a solution. If we are able to induce other changes in Scrophularia besides those shown, they will be quite as important in demonstration of the fact that germ-plasm had been modified as if they were exact repetitions of previous inductions. If previous results were exactly recalled there might be some suggestion of premuta- tion. It is evident that the experimenter who wishes to proceed with the greatest precision and least loss of effort will first test the genetic strictness of his living material, ascertain the rate and manner and diffusion of solutions in the ovary and ovules, the time of pollination and the rate of development of the tube in reaching the egg. Next, the structure and number of ovaries and the traumatic reactions of the entire pistil are to be taken into account. Having also traced out the simpler features of pollination and fertilization, the operator should test the effects of various reagents which may neutralize pro- teins, including enzymes, or act as excitators or catalyzers. Without enlarging too much upon the difficulties to be encount- ered in the experiments described in this jmper, they may be illustrated by the fact that over fifty operations upon Scrophu- laria in July, August and September, 1914, at Carmel, Cali- fornia, were total failures, as the ovaries perished before reaching maturity. Finally, many present interests in phylogeny and genetics will be concerned with the nature of the evolutionary move- ment which is simulated by the alterations which have been induced experimentally by the method described. Some of [Vol. 2. 1915] 274 ANNALS OF THE MISSOURI BOTANICAL GARDEN these would unquestionably be designated as of a retrogres- sive character, such, for example, as the defection of a part of the color pattern of the corolla; others, such as the accentuated incision of the leaves and corollas and the development of the venation, as progressive alterations ; while still others may not with any substantial reason be assigned to either class. With reference to taxonomic criteria, it may be said that the di- vergent individuals are distinguishable at sight from the parental stock, but the real test of the characters presented is not their degree or kind of departure, but their stability and permanence indicative of actual modifications of the germ- plasm. THE RELATIONS BETWEEN SCIENTIFIC BOTANY AND PHYTOPATHOLOGY DR. 0. APPEL Mitglied der Kaiserlichen Biologischen Anstalt fur Land- und Forstwirtschaft, Berlin-Dahlem The ever-increasing importance of phytopathology is the result of the steady development of agriculture, forestry, and horticulture. In this way phytopathology has become a part of each of these sciences. In former times well-known botanists, such as Gleditsch, Martius, Caspary, de Bary, and Sachs did not estimate themselves too highly to concern themselves at times with phytopathological problems. In modern times, however, it is not often that a university professor of botany occupies himself with such problems. This is due partially to the specialization which has become a necessity in modern science. Above all, however, this is due to a peculiar concep- tion which looks upon the applied branches of applied natural science as something inferior to the pure natural sciences. It must, however, be said that we find exceptions even here, if we think of such scientists as Brefeld and De Vries. Agriculture has within a short time presented many problems to phytopathology, and of these the principal ones have been those of disease control. These problems were often solved in a hasty way, which, I must admit, lacked scientific thoroughness. But even in the solution of these problems many interesting facts were brought to light. But with the progress in working out these questions it became more and more evident that many of these problems could not be ultimately solved unless investigated in a thoroughly scientific manner. In criticising the plant pathologists it should not be for- gotten that most of them are for the greater part autodidacts. Until recent times there were no places where scientific phytopathology was taught. In Germany it was only the Ann. Mo. Bot. Gard., Vol. 2, 1915 (275) 276 ANNALS OP THE MISSOURI BOTANICAL GARDEN [Vol. 2 University of Munich, in which von Tubeuf has been and is still teaching the subject. In Austria, Hecke has been giving lectures for some years. In the United States there has been much progress in this line, due, no doubt, to the fact that plant diseases are of greater importance here than in any other country. As the number of chairs in phytopathology in our institutions of learning increases, however, the rela- tion between scientific botany and phytopathology will be- come more and more intimate. Among the factors which favor unusual ravages by vegeta- ble and animal parasites, I wish to mention the rapid develop- ment of agriculture by way of growing the same varieties or races over vast areas, the great fertility of the previously uncultivated soils, which often induced people to crop the soil and neglect rotation, and lastly the favorable climatic condi- tions, which not only favor the cultural plants but also their parasites. One of the oldest problems of phytopathology is the smut- problem. Since ancient times smuts have been among the most important plagues of our cereals, and long before we knew the cause of these diseases people tried to control them. But rational measures of control could not be developed before the cause of the disease was known. Julius Kiilm succeeded in clearing up the life-history of the stinking smut. This was the first distinct step in advance, but here, unfortunately, progress ceased for some time, principally because of the lack of knowledge concerning the taxonomy of the smut-fungi. All loose smuts of oats, wheat, barley, and the close smuts of oats and barley were united under the single species Ustilago carbo. This prevented the investiga- tions of the biology of the smuts, and it was not until the fact was demonstrated that various species of smuts were concerned that the way was opened for the proper investiga- tion of the biology and subsequently also of the control of the parasite. The development of our knowledge of the smuts was due to the biological facts demonstrated by Brefeld and Hecke. They discovered that infection takes place through the 1915] APPEL— PHYTOPATHOLOGY AND SCIENTIFIC BOTANY 277 flowers. This fact pointed out the way of control. The problem was to kill one organism, the smut-fungus, within another organism, the grain seed, without doing damage to the latter. Jensen by his empirical work had demonstrated that such a procedure was possible. The correct method of control, however, could not be worked out because of the lack of knowledge concerning the fundamental scientific facts involved. In order to establish such a firm basis, I, together with my assistant, Eiehm, studied the resistance of the smut- fungi to external conditions, primarily to the effects of tem- perature. When the mycelium was grown in water and other substrata we demonstrated the fact that the thicker-celled mycelium as well as the spores are more resistant to external influences than is the vigorously growing mycelium. How- ever, not only the smut but also the grain is more resistant in the resting period than when germinating. Therefore, we tried to bring the infected grain seed under conditions which cause the fungus to grow and which at the same time do not allow the seed to germinate. We succeeded in doing this by allowing the seeds to remain for about four hours in water at 25-30° C. If one then subjects the seeds to a temperature at which the mycelium is killed but which does not yet induce germination in the grain, it is possible to kill the mycelium in the seed without injuring the latter. In these investigations the key to the so-called hot water and hot air treatment was found, and it was then only a technical problem to build apparatus with which the desired results could with certainty be realized. For our conditions in Germany this latter problem has also been solved. We have constructed several pieces of apparatus of this sort, and the treatment of grain against loose smut has been introduced on many farms. But the smut-problem has not been solved for all cases. This is especially true in the case of the stinking smut in the United States. This disease is of the greatest importance in the wheat districts of Idaho. In Germany Tilletia Tritici is spread by the seeds and is controlled by seed disinfection. In Idaho it occurs so generally in the soil that disinfection is [Vol. 2 278 ANNALS OF THE MISSOURI BOTANICAL GARDEN of no avail. Losses of 25 per cent of the crop are not uncom- mon. The solution of this problem seems possible only by the breeding of disease-resistant varieties. It is certain that smut-resistant races of wheat exist. The problem is to find these varieties and, in case they are not sufficiently produc- tive, to cross them with other varieties until races which com- bine the desired characteristics are obtained. In the districts where smut occurs every year it is possible to find these races in an empirical way. But in general it is my opinion that all work of selecting and breeding should be prosecuted along fundamental scientific lines. It is therefore first of all necessary to determine to what characters the plant owes its disease-resistant qualities. When this has been accomplished it is next necessary to deter- mine to what extent the characters are heritable, that is to say, whether they appear in crosses as dominant or recessive. The great advantage of this method lies in the fact that it makes it possible to recognize resistant races (by the presence of the specific characters to which resistance is due) without infection experiments, which are uncertain owing to the influ- ence of external and unknown conditions. I have shown to you by this example that in the solution of a single phytopathological problem such diverse branches of botany as taxonomy, biology of the flower, fungus-biology, and inheritance are involved. The following examples will show that in addition other branches of botany are of import- ance in phytopathology. In exact phytopathological investigations it is a primary factor that one know the host plants and the parasites in detail. This information must be based upon thorough systematic knowledge. This seems to be very easy in culti- vated plants, the species of which are generally well distin- guished. Some cases, however, are more complicated. When we want to make studies of cereal rusts, it is not sufficient to know the races of cereals by their agricultural names. We must know to what botanical species they belong; our culti- vated wheats, for instance, comprise species of different sus- ceptibilities. 1915] APPEL — PHYTOPATHOLOGY AND SCIENTIFIC BOTANY 279 Much more difficult are the systematic relations of the fungi. Many experiments and publications are valueless because the identity of the fungus was not made sure of in every single case. These difficulties are greater in case the fungi in question belong to the Fungi Imperfecti, where very often only the name of the genus has been determined, while the species name was simply made from the name of the host. Moreover, the descriptions of these imperfect fungi are often so insufficient that it is impossible to identify the fungi after- wards, especially when they occur on other plants or on a different or unrecognizable substratum. Within a genus that is rich in species there have sometimes been erected so many species that there is no possibility of identification. We find an instance of this in the genus Fusarium. Several hundreds of species have been described; which of these are identical has not yet been made clear, and in many cases this may never be possible. We cannot always solve the problem by making use of the exsiccata of the author of the species. Moreover, on one species of host several species of Fusarium may be harbored, and the author has often considered them identical. It is further often impossible to find what fungus was the type of the author's description. In such a case the only alternative is a thorough reworking of the taxonomy. How extensive a work this may often involve is instanced by the genus Fusarium. To establish the fundamental facts regard- ing the taxonomy within this genus required four years of work on my part as well as on the part of my assistant, Dr. Wollenweber, who devoted all of his time to the subject. Even after the establishment of these fundamental facts, only a very small part of the species had been determined, and for another two years Wollenweber has been working up the remaining species. I wish only to point out in addition that there exist more genera of this type : Botrytis, Gloeosporium, and Alternaria and its relatives. Modern taxonomy of fungi cannot limit itself to the morphology of the species casually collected. It must have the help of pure cultures on various media, for in artificial culture additional differences show themselves. These differ- [Vol. 2 280 ANNALS OF THE MISSOURI BOTANICAL OAKDEN ences are not only biological, such as color formation and changes in the culture media, but also morphological, such as the form of the "Fuszellen" or basal cells of species of Fus- arium, and even gross, as, for instance, differences in form of colonies, etc. In the first place, artificial culture is of enormous value as it furnishes the proof of the presence or absence of a relation between different forms of fungi. This knowledge not only- gives us a better insight into the development of the organism, but also gives us most important information as to the methods of control. In the identification of bacteria cultural methods are abso- lutely necessary as these organisms cannot be determined otherwise. The determination of the host and its enemies is not only desirable on the ground given above, but also because it gives us opportunity for ecological observations. A disease occurs only when conditions are favorable to its development, and these conditions are often pointed out by the composition of the flora of the locality, of which my studies upon the dying-out of alder trees in Germany give you a clear proof. In different localities these trees are killed by a fungus, Valsa oxystoma. The fungus grows into the wood through wounds, especially where branches or twigs are broken off, and kills out parts of the cambium and the bark. The parts into which it does not penetrate remain alive. There was no doubt about the fungus being the cause of the disease, but there were groups of trees which, though the fungus was present, were not quite killed out, the damage done in these localities being much smaller. I hit upon the correct explanation of this con- dition through a study of the special character of the flora under the trees. It was a typical flora of pastures, in which occurred specimens of 7m pseudacorus and retreating areas of Carex paniculata. These two plants are typical inhabitants of the peats, or water borders. It was clear that the locality had been formerly of a peaty character. I could determine that recently the water level had been lowered for the forma- tion of artificial meadows. Without a knowledge of the flora this relation would never have been found, as these meadows 1915] APPEL PHYTOPATHOLOGY AND SCIENTIFIC BOTANY . 281 were situated behind a chain of hills. The depth of the ditches had changed the water level and prepared the right conditions for an attack of Valsa oxystoma. In another paper I have shown the importance of the work of E. Munch. 1 This work is a model as to the manner in which investigations of plant diseases upon a scientific basis should be prosecuted. And, therefore, I wish to come back in a more detailed way to the work of Munch. The fungous diseases of our trees belong, in general, to the most im- portant diseases, and we yearly lose millions on their account. But we did not know the factors upon which the appearance of such diseases rested until these were demonstrated by the work of Munch. It was known that many fungi attack woody plants under definite conditions. Sometimes closely related species of one genus of hosts behave differently and some- times only definite tissues are attacked. Lastly these rela- tions vary in different years or seasons in different localities. The difficulty has been that the cause of this variability was sought in the different soil conditions which might have an influence on the constitution of the tissues of the host, in external injuries — such as sunburn or frost, and in the period of development of the fungus. These factors, however, are not of fundamental importance in the question of the produc- tion or suppression of a fungous attack. Munch has proved through numerous experiments that the content of air in the tissues is the determining factor. The greater part of the wood-decaying fungi have a large air re- quirement and are able to grow only when a maximum of air is furnished. In the first place the content of air is dependent on the quantity of water, and the occurrence of this large class of plant diseases depends upon the water supply. Simi- larly, the quantity of solid substance may be of influence. Specimens with narrow annual rings are more resistant than those with broad ones, because there is less room for air in the former. The different annual rings of the same wood und pflanzen. Naturwiss. Zeitschr. f. Forat- u. Landw. 7:54-75, 87-114, 129-160. 1909. [Vol. 2 282 ANNALS OF THE MISSOURI BOTANICAL GARDEN may be attacked differently, which is supported by the evi- dence of many observers. Not infrequently do we find tree trunks in which only some annual rings have been infected, or in which the same ring is diseased on one side and healthy on the other. The decayed rings are always the broad ones. The same varieties have a different air content in different localities. In the neighborhood of water sprouts or vigorous branches, the tissues are rich in water and poor in air, and infections very often do not penetrate into such regions. We know now that poorly fed and crippled specimens are likely to be attacked; on the other hand, it seems clear that fruit trees which are richly fed with nitrogen are very sus- ceptible to canker. An abundance of nitrogen induces the development of a very loose tissue, which during drought is more subject to diseases than a firm tissue. We recog- nize the periodicity in the occurrence of many plant diseases, lor we know the fluctuations in the water content of a tree. The air content of the healthy bark of beeches in winter-rest is 19-20 per cent, and diminishes at the time of budding to 11 per cent, rising afterwards. This is correlated with Ihe fact that the canker, which in Europe is caused by Nectria ditissima, does its damage from autumn until spring, while this damage ceases during the vegetative period. This was pointed out by Aderhold, who, however, failed to recognize the cause. If once we know the absolute percentage of air necessary for fungous growth in the different kinds of wood, we may decide through direct investigation whether in certain locali- ties the danger of infection is large or small. We may test the different varieties and try to avoid the danger. By this method the control is not directed against the fungus, but against the conditions which make its growth possible. In other words, we use instead of direct control, measures which prevent the outbreak of epidemic diseases. You see by this example what an exactly planned scientific investigation may do, and you can recognize the application of these facts to the American conditions. In the irrigated districts the fruit trees have but few die-back diseases due 1915] APPEL PHYTOPATHOLOGY AND SCIENTIFIC BOTANY 283 to species of Valsa and other fungi. When, however, such diseases occur, you will find the cause in defective irrigation methods, which may be remedied by changing the irrigation system. It is of the greatest importance that the land be irrigated at the time the trees contain less water and plenty of air, and that the next irrigations be made in time to prevent an excessive decrease of the water in the tissues. Not all fungi, however, are dependent upon the air contained in the wood. This is, for instance, the case with Armillaria mellea, where the rhizomorphs bring a sufficient quantity of air into the inner tissues. Whoever has cultivated the fungus artificially knows that after a short time rhizomorphs are formed which grow deep into the medium. But the rhizo- morphs are not formed on all kinds of trees and it may be possible that the fungus in these cases depends on the air already in the wood. Another question of great importance for American con- ditions is the question whether the growth of bacteria, prin- cipally of Bacillus amylovorus, is dependent upon the air con- tent of the host or not. These experiments must be sup- ported by thorough physiological investigations. That manner of control which seeks to remove the bacteria by cutting out the branches does not guarantee success for the future. I have been convinced of this in my trip through the United States, where I visited districts in which this control measure was thoroughly carried out. It may be possible that not only trees, but also herbaceous plants, show relations between fungous growth and air con- tent. I think it must be so for the organisms which cause the wilt diseases and the rhizoctonia disease of the potato, both of which have a high air requirement. On media poor in air these fungi grow only on the surface and absorb very eagerly the oxygen of hydrogen peroxide. The growth of Rhizoctonia in the well-aerated peat soil of the Stockton Delta and the forest soil of Germany is more marked in the dry years than in the years when the plants get a sufficient supply of water. In the United States these diseases are wide-spread, princi- pally through the irrigated lands. In my trip I came to the [Vol. 2 284 ANNALS OF THE MISSOURI BOTANICAL GARDEN conclusion that these diseases are not to be controlled by fighting the fungi, but by influencing the potato plant. Though caused by a fungus, the production of the conditions favora- ble to the progress of the disease is attributable to irrigation. In many cases the root system was poorly developed, the dif- ferent kinds of irrigation showing an influence upon the growth of the underground parts of the plants. We know very little of the conditions of growth of the potato in spite of a lew publications on this subject by Miiller-Thurgau, De Vries, and Vochting. Moreover, we know nothing about transpiration and water requirements in these plants or about their ability to form roots, or the factors that influence these processes. It is, therefore, very important that Shantz, of the Depart- ment of Agriculture, has actually undertaken the investigation of these problems. Others must follow him as soon as possible to solve these questions for the irrigated lands. The chemical-physiological side of the phytopathological questions also needs more attention, as has been pointed out recently by me and others in work upon the freezing problem. For a true judgment of the resistance to frost, in the case of cereal diseases, Gossner has apparently found the right way. The earlier stated fact that the cells of small pieces of tissue floating on a sugar solution are less quickly killed by frost than when floating in water, made it probable that the young plant is protected by sugar against frost in- jury. The investigation of the winter and summer rye shows that the sugar content of the former is several per cent greater than of the latter. The same is the case for frost-susceptible races of wheat. We may thus find out the relative frost re- sistance of closely related races of plants by determining the sugar content. But other phases of chemistry are of importance in phy- topathological investigations, as, for instance, the chemistry of colloids, which, as Euhland showed in his work, is of great value. The microchemical reactions are also of great importance. We know today that cork formation in the potato is a protection against bacterial invasion. I could show by using the reaction of Tisson that the deposition of 1915] APPEL PHYTOPATHOLOGY AND SCIENTIFIC BOTANY 285 cork in the cell walls near the places of infection occurs earlier than the formation of cork plates. Of special interest is the physiology of inheritance. In this lecture I wish merely to emphasize that the inheritance of the unit characters and their behavior in the next generation is one of the fundamentals of breeding resistant races. Finally, I must speak of anatomy. The necessity of the examination of series of sections oblige the pathologist to make use of the latest discoveries in histology. It is by way of anatomy that we shall approach the problem of leaf-roll of the potato. Onemjer has shown that the sieve tubes, which have the function of providing the plant with albumen, are destroyed in the leaf-rolling plants, similar symptoms occur- ring in plants which suffer from other diseases only when the plants are nearly dead. In leaf-rolling plants, however, we find these changes from the very beginning, and we may use them in diagnosis. Anatomy, likewise, points out relations be- tween external disease symptoms and inner changes of struc- ture. For instance, the three inner diseases of the potato, leaf- roll, wilt, and bacterial ring disease, have distinguishable anatomical characters ; the leaf-roll is a disease of the phloem ; wilt, of the secondary wood vessels ; and bacterial ring, of the spiral vessels. A thorough anatomical knowledge is of pri- mary importance in all investigations concerning the inner structure of healthy and diseased plants, the formation of excretions and tyloses, and the different ways of recovery. I hope that it has been possible for me to show you that phytopathology has many fundamental relations to scientific botany, and that it further presents many important problems for scientific investigation which deserve attention from the botanical departments of universities. Should I have succeeded hereby in winning new friends to phytopathology in this sense it would be a source of genuine satisfaction and pleasure to me. THE LAW OF TEMPERATURE CONNECTED WITH THE DISTRIBUTION OF THE MARINE ALGAE WILLIAM ALBERT SETCHELL University of California What I have to bring before you is simply a preliminary consideration of the general subject of the geographical dis- tribution of the marine algae together with some inquiry into the conditions immediately affecting such distribution and as possibly effecting a segregation into the larger units. In accordance with such an intention, I have started a tabula- tion of all the marine species and varieties, which is far from being completed as yet, but which has, however, reached a stage at which certain general statements may be made as to probable results. The geographical distribution of the marine algae has been treated of in various ways and in many papers. It is more or less customary to make a comparison between a particular flora and other more or less corresponding floras in com- parative tables, percentages of common and endemic species, etc. Certain speculations, based on such data, as to the origin of certain algal floras have also been indulged in. The result is that we have certain geographical areas fairly well marked out and certain others more or less indistinctly out- lined or surmised. Certain ecologic classifications have been proposed, particularly as to zonal occurrence in varying depth, influence of varying degrees of salinity, character of the sub- stratum, influence of surge, quiet waters, etc. Very little attention, however, has been paid to general factors control- ling distribution over larger areas. We speak broadly of tropica] species, or of arctic or antarctic species, of temperate species, etc., but no attempt has been made to survey the distribution of marine algae in general throughout the oceans and seas of the world and to attempt to determine the limit- ing factors segregating one large area from another. An attempt to determine how far our present knowledge of Ann. Mo. Bot. Gard., Vol. 2, 1915 (287) [Vol. 2 288 ANNALS OF THE MISSOURI BOTANICAL GARDEN species and their distribution may further such an inquiry is the object of the present paper. Among the more general discussions, there are to be men- tioned first those connected with the geographical distribu- tion in the Arctic Ocean. Kjellman's extensive and funda- mental paper 'Algae of the Arctic Sea' ('83) led the way and placed at the disposal of future students a very con- siderable amount of data and brought forward certain funda- mental points of view as to a division of the arctic marine ilora into provinces, as well as a consideration of the condi- tions underlying this division. This work was the result of the working over of very considerable collections of the vari- ous Swedish expeditions into the Arctic Ocean and a careful examination of all other existing data. Later, Rosenvinge ( '93, '98, '98% '98") published a series of papers dealing with the marine flora of Greenland, and Jons- son ('03, '03% '04, '12) has also published on the same subject as well as on the algae of Iceland and Jan Mayen. Finally, somewhat over twenty years after Kjellman's paper, Simmons ('05) surveyed the whole matter, revised all tabulations of the Arctic flora and brought forward further views together with a full discussion of all literature bearing upon the subject. In these various papers and others not referred to specific- ally, the North Polar Sea is defined and delimited from the Northern Atlantic and Northern Pacific Oceans. The condi- tions under which marine algae occur in the Polar regions as well as the differences between the conditions of the various portions of its waters are also determined and discussed. The North Atlantic has also been treated of, but more flor- istically than as to uniformity, or differences, of physical con- ditions affecting the flora. A considerable part of the discus- sion regarding the North Atlantic Ocean has centered about the Faeroes. Simmons ('97), Borgesen ('02, '05), Por- sild and Simmons ('04), and Borgesen and Jonsson ('05), have discussed the marine flora of these islands together with its relation to other North Atlantic floras and ocean cur- rents. Reinke ('89), Svedelius ('01), and Kylin ('06, '07), 1915] SETCHELL — DISTRIBUTION OF MARINE ALGAE 289 have considered the algal flora of the Baltic Sea and its rela- tion to that of the North Atlantic from points of view both floristic and as to physical conditions. Harvey ('58), Far- low ('81), and Collins ('00), have dealt similarly with the algal flora of the northeastern coast of North America, and Borgesen and Jonsson ( '05) have made an extended floristic comparison between the floras of the North Atlantic and those of the polar or arctic seas. For the antarctic and subantarctic regions, the work even of floristic comparison is still hampered by incomplete knowl- edge. The foundations were laid by Hooker ('45) in the 'Cryptogamia Antarctica' in which there are scattered notes on distribution. Skottsberg ('06) published his ' Observa- tions on the Vegetation of the Antarctic Sea' and later ('07) the first part of his antarctic and subantarctic work. The latter has only floristic details with notes on distribution. Gain ('12) has given a detailed discussion of the distribution of the marine algae thus far credited to either the antarctic or the subantarctic regions of the western hemisphere. Mur- ray and Barton ('95) have given a comparison between the arctic and antarctic marine floras, and Mme. Lemoine ( '12) has made a similar comparison limiting it, however, to the species of crustaceous Corallinaceae. The distribution of marine algae in the warmer portions of the oceans, Atlantic, Pacific, and Indian, has not been so much considered as that of the colder portions, although very considerable floristic work has been done. Murray ( '93) pub- lished a comparison of the marine floras of the warm Atlantic, Indian Ocean, and the Cape of Good Hope. Yendo ('02) has made definite statements about the distribution on the coasts of Japan. Saunders ('01) and Setchell and Gardner ('03) have dealt with the northwest coast of North America, and Schmitz ('96) and Schroeder ('12) have called attention to the relations between the marine flora of East Africa and those of the East Indies and of the central Pacific Ocean. Various papers and floras have considered distribution, such as bathymetric zonal distribution or according to vary- ing substratum, salinity, etc., within limited regions, prov- 290 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 inces, or districts, but no general paper has as yet appeared dealing with the distribution over the oceans in general or any definite suggestions as to the factors concerned. The nearest approach to an attempt to account for the gen- eral facts of distribution is my own attempt (cf. Setchell, '93) to explain the main facts of the geographical distri- bution of the Lamina riaceae. The plants of this family are rather inhabitants of the colder than of the warmer waters, proceeding, as it were, from the poles towards the equator, but lacking in strictly tropical waters. It was found that the Laminariaceae flora changed its facies with every increase or decrease of 5°C. of summer temperature, thus forming latitudinal zones controlled by temperature relations. This idea was extended to explain the demarcations of the floras of the west coast of North America by Gardner and myself (cf. Setchell and Gardner, '03) with apparent adequate reason. In attempting to discuss the more general facts of distri- bution we first necessarily consider the various marine floras and their subdivisions. While the term flora has been used in all sorts of senses, both wider and narrower, to include any aggregation of plants of any region under discussion, whether larger or smaller, it generally carries a certain idea of uni- formity of composition with it when used in connection with the floristics of distribution. This uniformity may, however, be only as regards region. It is desirable, here, to use the word for the aggregation of species of marine algae found in a certain region, province, or district, having a certain fairly considerable percentage of species in common through- out its extent, even of the more extended region. The world's surface, whether land or water, is usually divided into zones of temperature, these in turn into regions, the regions into provinces, and the provinces into districts. For marine floras, the districts must be still further divided into formations, and these in turn into bathymetric or littoral belts. The bathymetric belts, in their turn, show different algal associations. 1915] SETCHELL DISTRIBUTION OP MARINE ALGAE 291 Considerable work has been done in the description of various floristic associations occurring in various depth belts and of various formations, and the special ecological relation- ships have been discussed and made reasonably plain. My intention, however, is to discuss the broader distribution and segregation of floras, particularly as to regions and perhaps provinces and to attempt to determine the factor, or factors, governing these. In attempting to mark out the various floristic regions and their provinces, we are met with certain difficulties. The flora of the Arctic or Boreal region is fairly definite and has been the most carefully studied and tabulated. The prov- inces of the Arctic region are the Asiatic, the American, that of West Greenland, and the extended province of Spitzbergen (cf. Simmons '05). The North Atlantic Ocean as distin- guished from the Arctic has five regions, viz., those of North- western Europe, Southwestern Europe, and the Mediterraneo- Northwest African region on the east and Northeastern North America and Middle eastern North America on the west. The Antarctic or Austral region possesses a fairly consistent flora and is not so readily divided into provinces, but the Antarctic- Magellanic province may be contrasted with the Indo-Pacific province. The South Atlantic Ocean has a flora as yet little understood, but, for the present at least, may be considered to have the regions of Southwest Africa and Southeast South America. The Northern Pacific has Bering Sea probably representing a province of the Arctic or Boreal region. Otherwise it is divided into five regions, viz., those of North- west North America, Middle "West North America, and South- west North America on the east and the Ochotsk-Yeso region and that of East and West Honshu (or Nippon) on the west shores. The South Pacific Ocean has five regions, viz., those of Southwest South America, Middle West South America on the east and those of New Zealand and South and South- east Australia on the west coasts. The southern portion of the Indian Ocean has two regions, viz., that of Southwest Australia and the South Africa or Cape region. The tropical waters may probably be divided into two regions, viz., the [Vol. 2 292 ANNALS OF THE MISSOURI BOTANICAL GARDEN Tropical Atlantic and the Indo-Pacific regions with their proper subdivision into provinces. Concerning these various regions, it may be said that some seem to possess very dis- tinct and characteristic species content while others are more or less related to one another. However, it is expected that there will be a possibility of discussing this segregation at another time in more extended fashion. Of particular interest and importance in connection with the marking off of floristic regions, are the points or areas of demarcation. Some of these are well established while others may be only more or less accurately surmised. One of these much referred to in the literature (cf. Harvey, '58; Farlow, '81; etc.) is Cape Cod on the eastern coast of Massa- chusetts which divides so clearly and so accurately the flora of northern New England from that of southern New England. Cadiz in Spain appears to be another point of de- marcation, or possibly indication of an area, where the flora of the Southwestern European region stops, or mingles with that of the Mediterranean-Northwest African region. At Clare Island on the west coast of Ireland (Cotton, '12, p. 160) the flora "resembles that of the southwest of England," but it has elements also of a distinctly northern character. It is probably in or near a demarcation area. Similarly southern Norway and the west coast of Sweden (Kjellman, '02, '06; Svedelius, '01; Kylin, '06, '07) have a mixed flora and are in a transition region. In Japan Cape Inuboi on the east coast of Honshu (cf. Yendo, '02, p. 181) is a demarcation point and the Strait of Sangar (cf. Yendo, '02, p. 182) is also a region of demarcation or transition. On the opposite side of the Pacific Ocean, along the western coast of North America, Cape Flattery or just south of it, Point Conception, and the region about the mouth of the Gulf of California are demarcation points or indicate transition areas (cf. Setchell, '93, p. 370; Saunders, '01, p. 393; Setchell & Gardner, '03, p. 170). In the southern hemi- sphere the marine flora of the Cape Rogion is definitely de- limited both to the southwest and to the northeast and in 1915.1 SETCHELL DISTRIBUTION OF MARINE ALGAE 293 Australia the marine flora of the southeastern region is defi- es nitely set off from that of the southwestern region. These various points and regions will doubtless become more definite and more of them will become established as careful investigations of the floras are made. They un- doubtedly indicate that thereabouts are changes in the con- ditions regulating the separation of the general flora into its larger divisions and are of great importance in any inquiry as to the general factors affecting the distribution of marine algae. Along with the mapping out of floras into regions, provinces, etc., it seems best to consider, next, the factors which seem to regulate the distribution. These have been considered by Kjellman ('83) and by others, and are summed up by Oltmanns ( '05). Particularly is it desirable to consider which may be chiefly responsible for the limiting of the species within the regions or provinces. The substratum exercises an important influence on the attached flora or benthos and that is particularly the part of the marine flora I intend to limit this paper to, since the plankton brings in certain particular factors having to do with its floating habits. Of course, benthos can only exist on its proper firmer substratum and different species differ in the nature of this. However, it is sufficiently evident that the character of the substratum limits species only locally and can by no means be considered as a factor in controlling floral regions or even floral provinces. The motion of the water is a limiting factor in distribu- tion, some algae preferring quiet water, some flowing, some surge, etc., but this factor, too, is clearly a local and not a general one in the distribution of the marine algal benthos. The specific gravity of sea-water varies and with it, of course, its salt content. This variation, so far as marine algae are concerned, varies from water only slightly brackish to that (in case of exposed and shallow tide pools) of an almost concentrated solution. There is a latitudinal zonal difference here also, but it is not so great as may be found in localities at no considerable distance from one another. It [Vol. 2 294 ANNALS OF THE MISSOURI BOTANICAL GARDEN certainly seems impossible that this can be a general factor. Its local effect, however, may be very considerable. Light varies from the equator, where it is most intense, to the poles where it is least. It very decidedly limits the dis- tribution as to depth. Marine algae of the benthos need light and are, therefore, limited to the neritic portion of the photic zone as to their general distribution. Outside of this general limitation, however, it does not appear that the varying in- tensity of light can be considered as a prime factor in limiting floral regions and floral provinces, i.e., not alone. Varying temperature, however, does act directly upon algae to limit their distribution, both locally and generally. It can easily be recognized to be the one most important factor in controlling the distribution of benthos over wide areas as well as, at times, in smaller districts or spots. We recognize that, in general, the species of the frigid zones, of the tem- perate zones, and of the tropical zones are sufficiently different to give an entirely different facies to each. Yet, in consider- ing general regions, we find that they are not marked out by the same parallels as are used to mark these zones geographic- ally. These geographical zones, however, are established more particularly as regards direction of the sun's rays and the temperature of the air rather than that of the water. The waters concerned with the life and persistence of the algae, even of the benthos, are, relatively speaking, the sur- face waters, since algae seldom grow lower than at a depth of 100 meters and for the most part cease at 20-30 (or at times 40) meters. The normal decrease in temperature at such depths is slight even in temperate waters, although, at times, sufficient to account for special sporadic anomalous distribution. The range in temperature under which algae, in general, may carry on their full course of vegetative and growth activities is from — 2°C. up to the neighborhood of 90° C, but that for marine algae is only from — 2°C. up to 30 C C. (or possibly 32°C), this being the extent of ranges for all surface waters of the ocean. A comparison between charts in which the isotherms for surface temperature of the water of the oceans are laid off 1915] SETCHELL DISTRIBUTION OF MARINE ALGAE 295 shows a definite correspondence between certain of these and the boundaries of different marine floral regions as previ ously laid out and indicated in this paper. From the point of view of the distribution of the marine benthos, so far as algae are concerned, it is found by practice to be satisfactory to divide the surface waters of the ocean into nine zones, as follows: Upper Boreal, Lower Boreal, North Temperate, North Subtropical, Tropical, South Sub- tropical, South Temperate, Lower Austral, and Upper Aus- . The limiting isotherms of surface temperature chosen those of the summer month or maxima, viz., the isotheres, tral which are those of February (or bly March) for the southern hemisphere and those of August bly Sep tember) for the northern hemisph These lines are laid down with approximate accuracy in the charts of the atlases of the different oceans published by the ' ' Deutsche Seewarte ' ' of Hamburg ( '92, '96, '02). These isotherms are more accurate and explicit for the open ocean than for the neritic zone where the algal benthos occurs, but, with certain allowances, the as indicated are sufficiently accurate. Each of the zones I have proposed covers 5°C. range of surface temperature with the exception of the Upper Boreal and the Upper Austral, each of which includes a range of 10°C ■ » ghtly trarily adopted, are between the isotheres of 0°C r. The zones, then, more or less arbi the Upper Boreal and Upper Austral even 2°C to 10°C Lower Boreal and Lower Austral between the isotheres of 10° C. and 15° C, North Temperate and South Temperate between the isotheres of 15° C. and 20°C., North Subtropical between the isotheres of 20° C. and and South Subtropical betwee 25° C, and the Tropical between 25° C. and 30° C. (or above). These 5°C. zones are thus laid out according to the 5 isotheres, because on inspection these isotheres approach most closely or touch the shores at the drv points of floras and pal floral They have been de termined empirically, and indicate, as it seems from ence in working with them, that they coincide with floral boundaries the oceans over more exactly than do any of the 296 ANNALS OF THE MISSOURI BOTANICAL GARDEN rvoL. 2 winter isotherms or isocrymes, or any of those in the inter- mediate seasons. For example the isothere of 20° C. passes somewhat south of Cape Cod to the eastern end of Long Island, but the shal- low and more or less protected waters of Long Island Sound, Narragansett Bay, Buzzard's Bay and Vineyard Sound carry a higher temperature eastward even to the Cape Cod region. At exposed points, however, the somewhat colder waters of the ocean outside exist and exercise their influence at exposed points or in deeper waters. Again at Cadiz, the isothere of 20° C. abruptly curves up to the coast. At Cape Inuboi, Japan, the isothere of 25°C. touches land and at the Strait of Sangar, that of 20° C. The Cape Region of South Africa is included between the isotheres of 20° C. and 25 °C. Similar relations hold good on the coast of Ireland, for the 15°C. isothere comes in just north of Clare Island at about Annagh Head. On the south coast of Australia, the isothere of 20 °C. touches the east coast just above Cape Howe and the south coast about Cape Arid, thus leaving the southeastern coast below 20°C. of average summer temperature and the southwestern coast above it. Although the western coast of North America has its tem- perature relations very much disturbed, as I shall indicate later, yet there is a fairly definite relationship to the isotheres of 10°C, 15°C, 20°C, and 25°C. The arctic or boreal floristic region has a definite southern boundary in the 10 °C. isothere and the subarctic in that of 15°C, while those of the North Atlantic are bounded to the south by that of 25 °C. The strictly tropical species are found almost entirely between the isotheres of 25°C. and 30°C. (or 32°C). It is expected that a later paper will deal more definitely and in more detail with the reasons for selecting the isotheres as boundin for the temperature zones. e> Two seeming disturbances of those zonal areas may be noted ( Upper and Upper Austral) are for 10°C. interval rather than 5°C. This is in accordance with what is known of the distribution of the marine flora in the higher Arctic and the higher Ant- 1915] SETCHELL DISTRIBUTION OP MARINE ALGAE 297 arctic regions, where there seems to be no useful purpose served in segregation by assuming two zones rather than one. The second disturbance of zonal areas is through the occurrence of local areas, of greater or less extent, of water of a higher or lower temperature than is normal for the gen- eral zone. Colder waters occurring among warmer waters are found along the west coasts of North and of South Ameri of northwestern and southwestern Africa, and of northeastern Africa. These are due to rents to up- wellings of cold water. Their existence is well substantiated but their cause is still a matter of discussion among ocean- ograpb When warm waters exist among colder waters they occur as "spots" or small areas where the higher tern perature is due to comparal general oceanographic condit local factors apart from Such disturbances as ud- wellings and spots may bring about a puzzling discontinuity in the distribution, very puzzling, indeed, until the immediate cause is discovered. Another matter causing seeming disturbance of the limits of temperature zones proposed is the seasonal variation of the temperature of the surface waters. This is variable, but in general may be considered to hold true as follows: The seasonal surface temperature variation as platted for 2° squares is least in the Upper Boreal, Upper Austral and Tropical zones, where it is not over 5°C. in range; is greatest in the Temperate zones where it averages nearly 15° C. and may be as great as 27 or 28° C, and is medium in the Subtropical zones and in the Lower Boreal and Lower Austral zones where it approximates 10° C. These, then, are the principal features of temperature dis- tribution with which we may be concerned. In connection with the empirical establishing of the temper- ature zones previously outlined, I have attempted to arrange each and every species of marine algal benthos thus far described in the zone or zones to which it has been accredited. The work is not as yet by any means completed, but a general view has been obtained for the Rhodophyceae, Phaeophyceae, Chlorophyceae, and Myxophyceae, and the greater part of the [VOL. 2 298 ANNALS OF THE MISSOURI BOTANICAL GARDEN Rhodophyceae have been worked out in fair detail, although no percentages of absolute accuracy can be given at present. The general results are as follows: (1) The greater part of the species are known from one zone of temperature. (2) A considerable number of species are known from two zones of temperature. (3) A comparatively small number are credited to three zones of temperature. (4) Species credited as occurring in four or five zones of unlike temperature are extremely few and almost always doubtfully so accredited. (5) There is a change of facies of the flora in each suc- cessive zone, i.e., with every increase or decrease of 5°C, excepting in the cases of the Upper Boreal and the Upper Austral. This means that most species are, so far as known, confined to zones of amplitude of 5°C. of summer temperature, that certain species extend over zones representing 10 °C. ampli- tude, while a few may extend over zones representing 15° C. amplitude of summer temperature, and extremely few defin- itely known in zones covering over 20° C. amplitude of sum- mer temperature. To mention the results of the preliminary survey of the marine Rhodophyceae so far listed and checked, may give approximate conditions which also seem to exist in other groups. The species and varieties thus far accredited to this group number about 3,350. Of these the northern hemi- sphere has about 34 per cent in its extratropical waters, the southern hemisphere approximately 44 per cent, whilo the tropical waters have approximately 22 per cent. Of the entire number, approximately 71 per cent are confined of temperature; about 21 per cent extend over two succes- sive zones of different temperature; about 6 per cent are accredited to three successive zones of different temperature ; while between 1 and 2 per cent are accredited, but with more or less, generally very considerable, doubt, to four, or even to five, successive zones of different temperature. 1915] SETCHELL DISTRIBUTION OF MARINE ALGAE 299 Commenting on the above, it may be surmised that the percentage in one zone is high on account of many new or little known species which have been collected only once, while the percentage of species occurring in two successive zones of different temperature is low because of our incomplete knowledge. Concerning the species credited to three zones, the percentage is small but perhaps not much lower than will be found on final careful revision. Here seasonal occurrence and "spot" distribution will undoubtedly be found to be con- cerned in the overlapping, as it will be also in the case of overlapping in two zones. Concerning the occurrence in four or five successive zones of different temperatures the percent- age although small will, with very little doubt, be decidedly decreased or even entirely erased when the doubtful cases are investigated and cleared up. There may be a fraction of one per cent still left, however, and if there is, I doubt not that some fairly simple physiological explanation of their toleration of such an extreme range of temperature will be found. The disturbances in the uniformity of regular in- crease or decrease in the temperature of surface waters, as referred to latitude, have already been mentioned as due to cold upwellings and spot variation according to local physical peculiarities. These disturb, of course, the zonal distribution. Where such intrusive areas of colder or warmer water are extensive, the distribution in those areas must be considered in connection with the nearest zone of similar temperature. Spot distribution also, may be so referred but only in general considerations of distribution. Otherwise it must be con- sidered specially. The disturbance of regular zonal distribution which must have special consideration from the zonal point of view is that which arises from seasonal variation in the surface tem- perature accompanied by seasonal occurrence of a certain ele- ment of the flora in some district or province of a region of the particular zone. Seasonable amplitude varying on an average from about 5°C. to 15° C. in extent, as I have mentioned before, is found in the various temperature zones. Seasonal duration, or, at [Vol. 2 300 ANNALS OF THE MISSOURI BOTANICAL GARDEN least increased seasonal vigor in certain elements of the flora is found in all zones, a phenomenon of mixed dependence upon light and temperature. It is most marked in the Temperate zones but is to be found in the Subtropical, Lower Boreal and Lower Austral zones as well. In the Upper Boreal and Upper Austral zones its appearance is perhaps more associated with varying intensity of light than with temperature, and it is least pronounced in the Tropical zone, where it seems to be wholly dependent upon light variation. It is certain that many boreal summer species appear as winter or early spring species in the Temperate zone and like- wise certain temperate species appear during the colder sea- son in the Subtropical zone. There is some, but apparently not very much, overlapping between the upper portions of the Subtropical zones and the Tropical zone. From the very incomplete studies thus far made, it seems that most species range through from 5 to 10° C. of temperature, that each zone has its own characteristic species and that extensions up to 15° C. for active growth and reproduction are few, if at all existent. More careful examination, however, is neces- sary to satisfactorily demonstrate this last point. While the limits of the temperature zones have been founded on the isotheres or lines of average daily summer temperature, seasonal phenomena cause us to consider also the isocrymes or lines of average daily winter temperature, especially as to overlapping or transitions between the zones. The isocrymes are of especial importance in those portions of certain zones where, especially on account of strong currents, the seasonal variation is extreme, e.g., on the eastern coast of North America and on the eastern coast of Asia. In such regions there may be expected extreme expression of seasonal change of flora. The disturbances of distribution due to upwellings cause confusion in the tabulated results unless they are to be defi- nitely accounted for. This confusion is greatest at present in connection with the species of the central coast of California. Spot distributions also cause the species concerned to be tabu- lated in more than one, or, if combined with seasonal disturb- 1915] SETCHELL DISTRIBUTION OF MARINE ALGAE 301 three Spot distributions less easy to enough are detect than other anomalous distributions but sufficiently known to make apparent their influence and im portance in any scheme of representation of geographical distribution. While the distribution of any particular of plant depends upon a complex of conditions controlling continued existence, both vegetative and reproductive, certain more general factors may be distinguished as prevailing over larger areas, while others, less general, may account for local and usually discontinuous distribution within particular provinces and districts, and as components of various formations, bathy metric belts, and associations. Temperature has come to be considered as one of the most important of the conditions controlling, or governing, the dis- tribution of plants and animals (cf., e.g., Merriam, '94, '98, etc.; Livingston and Johnson, '13; and others). Any bio- logic factor has, of necessity, two variables (cf. Livingston and Johnson, '13, p. 351), intensity and duration, and ables present considerable m the case of land plants. For marine plants, particularly for those species tantly submerged amplitude of variables is less than for the land plants. The surface waters of the ocean, while influenced by the temperature of the air, change slowly and only within cert limits Mo con- siderable is the variation through the influence of pwell Yet on the whole the temperature variables are seemingly, at least, much less in amplitude than are those of the land. For those plants exposed during tidal changes the temperature variables may be considerable in amplitude. Yet such are only occasional and of short duration, except, perhaps, for the plants of the uppermost tide limits. One matter of import- ance as to all factors in plants submerged entirely or for the greater portion of the time, is the uniformity of exposure to the same conditions. While the land plant may have its roots buried in the soil of one temperature and its aerial organs exposed considerably different temperature, the entire 302 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 surface of the submerged plant is exposed to one and the same temperature. The problem, therefore, of temperature as a physiological factor in controlling the distribution of algae, in general, and of marine algae in particular, is, as com- pared with that of land plants or of land animals, compara- tively simple. Any attempt to unravel the physiological basis for the con- trol of distribution must be, at this point of the progress of the work, lacking sufficient data for conviction. The state- ments presented merely represent approximate optimal con- ditions for the duration, succession, and, therefore, continued persistence of the species of the various life zones. It seems certain that the coefficients for continued existence vary among the different species, but are restricted in the case of each species to about 10° C. in amplitude. There must be for each species a certain minimum and a maximum of optimal temperature for continued life and reproduction. It is pos- sible that certain species may continue to exist outside these, especially if they possess powers of vegetative reproduction. Thus far, it has been in mind to attempt to determine co- efficients of efficiency as Livingston and Johnson have sug- gested in the case of climatic factors controlling the distribu- tion of land plants, but no real beginning has, as yet, been made. The interval of 10 °C. certainly suggests the working of the van't Hoff-Arrhenius principle as applied to vital phenomena. Taking the variation of 10° C. as the control- ling interval of temperature and regarding it as an index to the summation of temperature, it may be possible in a later paper to definitely estimate the coefficients of temperature- efficiency in a fashion similar to that already suggested by Livingston and Johnson ('13) for land plants. If the rate of the vital activities are, in general, doubled or nearly so with each increase of 10°C, then, judging from the results of the Rhodophyceae, thus far tabulated, it would seem that marine algae cannot endure an acceleration greater than 2, that each species has its own definite initial tempera- ture for efficient vegetative and reproductive activity and that such initial efficient activity may be accelerated up to the 1915] SETCHELL DISTRIBUTION OP MARINE ALGAE 303 doubling point, but not beyond it. plained the fact that from 0°C. (or — 2°C.) to 10 °C. of In this way may be mean su mm er temperatur Boreal and Uriner Austral marks the limits of the Upp at The marine algae inhabit these zones are subjected to a range of not over 10° C nv. or all. times. The snecies enduring a mean summ species of the Temperate zones, temperature of 10° 0. to 15° C. have a range of 10 to 12 °C, probably not over, at any or all times. Similarly those of the Subtropical and Tropical zones endure a range of not over 10° C. If, therefore, tentatively, a temperature efficiency coefficient be estimated according to the formula of Livingston and Johnson ( '13, p. 365) but modi- fied by leaving out the assumption of an initial temperature higher than 0°C, viz 2 t 10 the efficiency coefficient in the case of the Upper Boreal and the Upper Austral zones (0 to 10° C.) will be unity to 2, in case of the Lower Boreal and also the Lower Austral (10 to 15°C), will be 2 to 3, for the Temper- ate zones (15 to 20°C), the coefficients will be 3 to 4; for the Subtropical zones (20 to 25°C), the coefficients will be 4 to 5, and for the Tropical zones (25 to 30°C), the coefficients will be 5 to 6. Incidentally to carry out this idea of temperature efficiency coefficients, it may be said that the application to the case of thermal algae, where I find the 10° C. amplitude rule also to apply, would carry the coefficient index up as high as 16, i.e., in the case of those species enduring highest temper- atures (80°C), and even to 18 in the case of thermal bacteria (90°C). In conclusion, I may say that while much detail remains be considered and brought into order before the final data and conclusions may be published, I have reason to believe that the statements and conclusions I have either made or brought forward in this preliminary account, will probably not need be changed, at least to any great extent. List of Works Referred To Borgesen, F. ('02). Marine algae. Botany of the Faeroes 339-532. f. 51-110. 1902. , ('05). The algae-vegetation of the Faeroese coasts with remarks on the phyto-geography. Ibid. 683-834. pi. 13-24. f. 151-16^. 1905. [Vol. 2 304 ANNALS OF THE MISSOURI BOTANICAL GARDEN , and Jtinsson, H. ( '05 ) . The distribution of the marine algae of the Arctic Sea and of the northernmost part of the Atlantic. Ibid. Appendix: I-XXVIII. 1905. Collins, F. S. ('00). Preliminary lists of New England plants, — V. Marine algae. Rhodora 2:41-52. 1900. Cotton, A. D. ('12). Marine algae. Clare Island Survey, Part 15. Roy. Irish Acad., Proc. 31:1-178. pi. 1-11. 1912. Deutsche Seewarte-Hamburg ('92). Indische Ozean, ein Atlas. , ('96). Stiller Ozean, ein Atlas. •, ('02). Atlantischer Ozean, ein Atlas. [2nd ed.] Farlow, W. G. ('81). Marine algae of New England and adjacent coast. U. S. Fish Comm. Rept. 1879:1-210. pi. 1-1'). 1881. Gain, L. ('12). La flore algologique des regions antarctiques et subantarctiques. Deuxteme Expedition Antarctique Francaise 1908-1910. Sci. Nat. Doc. Sci. 1-218. pi. 1-7. f. 1-98. 1912. Harvey, W. II. ('58). Nereis Boreali-Americana. Part I. Melanospermea<\ Smithsonian Contr. 1-149. pi. 1-12. 1858. Hooker, J. D. ('45). The cryptogamic botany of the Antarctic voyage of II. M. Discovery Ships Erebus and Terror, etc. 1-258. pi. 57-11)8. 1845. J6nsson, H. ('01). The marine algae of Iceland (I. Rhodophyceae ) . Bot. Tids skrift 24:127-155. f. l-l t . 1901. , ('03). Ibid. (II. Phaeophyceae). Ibid. 25:141-195. f. 1-25. 1903. , ('03a). Ibid. (III. Chlorophyceae. IV. Cyanophyceae). Ibid. 337-385. f. 1-19. 1903. , ('04). The marine algae of East Greenland. Meddelelser om Gron- land 30: 1-73. f. 1-18. 1904. , ('12). The marine algal vegetation. In Warming, E., and Rosevinge, L. K., The Botany of Iceland 1: 1-180. f. 1-7. 1912. Kjellman, F. R. ('83). The algae of the Arctic Sea. Kongl. Sv. Vetensk. Akad. Handl. 20 5 : 1-351. pi. 1-31. 1883. , ('02). Om Algenvegetationen i Skelderviken och angriinsande Katte- gatts omrade. Meddelanden fran Kongl. Landbruksstyrelsen 2:71-81. 1902. , ('06). Om friimmande alger ilandrifna vid Sverigefl vastkust. Arkiv f. Bot. 5 1B :1-10. 1900. Kylin, H. ('00). Biologiska jakttagelser rc">rande algfloran vid svenska v&st- kusten. Bot. Notiser 1906:125-138. 1900. ('07). Studien iiber die Algenflora der schwedischen WestkUste. Inaug. Diss. 1-287. pi. 1-7. f. 1-43. 1907. Lemoine, Mme. Paul ('12). Sur les caracteras des genres Mdobesiees arctiques et antarctiques. Compt. rend. acad. Paris 154:781-784. 1912. Livingston, B. E., and Johnson, Grace ('13). Temperature coefficients in plant geography and climatology, Bot. Gaz. 56:349-375. f. 1-3. 1913. Merriam, C. H. ('94). Laws of temperature control of the geographic distri- bution of terrestrial animals and plants. Nat. Geog. Mag. 6:229-338. 3 col. maps. 1894. 1915] SETCHELL DISTRIBUTION OF MARINE ALGAE 305 , ('98). Life zones and crop zones of the United States. U. S. Dept. Agr., Biol. Survey, Bull. 10:1-33. 1898. Murray, G. ('93). A comparison of the marine floras of the warm Atlantic, Indian Ocean, and the Cape of Good Hope. Phycological Memoirs 2:65-69. 1893. , and Barton, E. S. ('95). A comparison of the Arctic and Antarctic marine floras. Ibid. 3: 88-98. 1895. Oltmanns. F. ('05). Morphologie und Biologie der Algen 2:1-443. f. 468-617. 1905.' Porsild, M. P., och Simmons, H. G. ('04). Om Faeroernes Havalgevegetationen og dens Oprindelse. En Kritik. Bot Notiser 1904: 149-180. 1 map. 1904. Reinke, J. ('89). Algenflora der westlichen Ostsee, Komm. z. wiss. Unters. d. deut. Meere in Kiel 1 col. map. 1889. deutschen Antheils. Ber. d. 6:III-XI and 1-101. f. 1-8. Rosevinge, L. K. ('93). Gronlands Havalger. Meddelelser om Gronland 3:765 981. pi 1-2. f. 1-57. 1893. , ('98). Om Algevegetationen ved Gronlands Kyster. Ibid. 20: 131-242. f. 1-i. 1898. , ('98a). Deuxifcme mgmoire sur les Algues du Groenland. Ibid. 1-125. pi. 1. f. 1-25. 1898. , ('98^). Sur la v£g£tation d 'algues marines sur les cotes du Gronland. Ibid. 339-346. 1898. Saunders, De A. ('01). Papers from the Harriman Alaska Expedition. XXV The Algae. Wash. Acad. Sci., Proc. 3:391-486. pi. 48-62. 1901. Schmitz, Fr. ('96). Marine Florideen von Deutsch-Ostafrika. Bot. Jahrb. 21: 137-177. 1896. Schroeder, B. ('12). Zellpflanzen Ostafiikas gesammelt auf der akademischen Studienfahrt, 1910. Hedwigia 52:288-315. 1912. Setchell, W. A. ('93). On the classification and geographical distribution of the Laminariaceae. Conn. Acad. Arts and Sci., Trans. 9:333-375. 1893. , and Gardner, N. L. ('03). Algae of northwestern America. Univ. Cal. Publ., Bot. 1:165-418. pi. 17-27. 1903. Simmons, H. G. ('97). Zur Kenntniss der Meeresalgen der Faroer. Hedwigia 36:247-276. 1897. , ( J 05). Remarks about the relations of the floras of the northern At- lantic, the Polar Sea, and the northern Pacific. Beih. bot. Centralb. 19 a : 149-194. 1906. Skottsberg, K. ('06). Observations on the vegetation of the Antarctic Sea. Bot. Studier 245-264. pi. 7-9. 1 map. 1906. , ('07). Zur Kenntniss der subantarktischen und antarktischen Meeres- algen. I. Phaeophyceae. Wiss. Ergebn. d. Schwedischen Sudpolar-Exp. 1901- 1903. 4:1-172. pi. 1-10. f. 1-187. 1907. Svedelius, N. ('01). Studier ofver Osterjons Hafsalgflora. f. 1-26. Upsala, 1901. Inaug. Diss. 1-132. Yendo, K. ('02). The distribution of marine algae in Japan. Postelsia 1:177- 192. pi. 19-21. 1902. PHYTOPATHOLOGY IN THE TROPICS JOHANNA WESTERDIJK Director of the Phytopathological Laboratory, Amsterdam, Holland Tropical life is a luxurious life Nowhere does plant and animal life show itself in such variety and abundance the equator. As the conditions in those regions are uncommonly fa\ able to plant growth, it would appear that the plant parasites also have a good chance of living. In several tropical coun- tries plant diseases have been studied in a more or less ex- tensive way, but the general features of plant diseases in the tropics, unlike those of the temperate regions, have hardly been touched. I have been for some time studying plant diseases in our colonies of the East Indies, the so-called Malayan Archipelago, and I wish to give you some general impressions on fungous diseases in those countries, remarks can be onlv suggestions, as thorough investig My far as I know on these tropical problems have never, so been made. The Malayan Isles have an average temperature of 30° C in the lower parts, accompanied by a humidity of 80-100 per cent. The climate is a monsoon climate. In the time of the wet season it pours every afternoon, but in the dry time the rains are verv scarce in the lowlands but not infrequent forest-covered mountain One would be inclined think that this combination of high temperature and moisture would be extremely favorable for fungous growth, and that therefore fungous diseases would play a large part in the culture of economic plants. This, however, is not the case. We find that insect troubles prevail, and that, compared with our temperate regions, few diseases exist. We would not conclude these facts from the literature, as a large number of diseases caused by fungi have been described. But in visiting the countries it struck me that only a few diseases are of real importance; a great Ann. Mo. Bot. Gard., Vol. 2, 1915 (307) [Vol. 2 308 ANNALS OF THE MISSOURI BOTANICAL GARDEN many of those described must have been found occasionally, and have had no serious influence upon the cultivation of plants. Not only among the cultivated plants do we find little fun- gous growth, but also in the natural vegetation. In the virgin woods the trees have few enemies among the fungi, and even the flora of mushrooms on the ground, so characteristic of our woods, is absent. Everything seems to point to the con- clusion that conditions are unfavorable to fungous growth. Why is this so? As has already been said, there are two conditions which characterize a tropical climate: (1) a high temperature which is about equal through all seasons, and (2) a high humidity, the latter varying somewhat in the dif- ferent monsoons, but being altogether much higher than in our climates. It seems to me that the tropical temperature is too high for many fungi. I cultivate in my laboratory over 600 fungi, and this collection shows clearly that the temperature of opti- mum growth of the greater part of the fungi lies beneath 30° C, often under 25 U C. An exposure to high temperature prevents many parasites from forming their spores or fruit- ing bodies, whereas others require a change of temperature for normal growth. The Polypor has either lost its function as a sexual organ or ascogone, or has disappeared. In such cases differentiation of sex occurs in special vegetative cells, sometimes by the migration of a nu- cleus from certain cells into adjacent ones. In Gnomonia erythrostoma, although Frank ( '86) described coiled ascogone- like structures with trichogynes, and believed that the coils were fertilized through the agency of the spermatia, recent cytological work (Brooks, '10) on this species appears to show that the tufts of hair-like structures emerging through the stomates of cherry leaves, on which this species of Gno- monia is parasitic, are not now connected with the coiled hyphae deeper in the tissue. It appears also from the same work that the ascogenous hyphae do not arise from the coils, but from one or more slightly differentiated hyphae in the center of each coil. A similar example is found in Xylaria polymorph a (Pisch, '82), where an extensively coiled hypha ("Woronin's hypha") occurs in the early stages of the formation of the ascocarp, but later disappears and certain vegetative cells give rise to the ascogenous hyphae. In Humaria rutilans (Fraser, '08) no archicarp or ascogone coil is discernible, but certain vegetative cells function as as- cogenic cells following the migration into them of nuclei from adjacent cells. MORPHOLOGY OF THE ARCHICARP If the history of the Ascomycetes is correctly read from the simpler and more generalized forms to the complex and 1915] ATKINSON PHYLOGENY IN THE ASCOMYCETES 355 highly specialized ones as Sachs (74, '96), de Bary ('81, '84), and many other students have advocated, the female organ or archicarp first appeared as a " unicellular ' ' or con- tinuous organ, not differentiated into an oogonium or fertile portion, and a trichogyne. The presence of a " 1 ' procarp, ' ' whether consisting of one or several cells, which ultimately gave rise to the asci or ascogenous threads was the predomi- nant character which led Sachs in 1896 to believe in the phy- letic relation of the sac fungi and red algae, although earlier he had regarded the morphology of the ascocarp and cysto- carp of greater importance in showing relationship. No known red alga possesses a procarp simple enough to repre- sent the prototype of the two groups. Gymnoascus was se- lected by Sachs as representing the simplest Ascomycetes. The archicarp of Gymnoascus is a continuous structure more or less coiled around the antheridium from which it copulates directly without the intervention of a trichogyne. After copulation the ascogonium divides into several cells which give rise to the ascogenous hyphae. In some forms the splitting up of the ascogonium by transverse division occurs at an earlier period, before copulation. There is some evi- dence which indicates that the ' * trichogyne ' | in the Ascomy- cetes primarily was a prolongation of the " unicellular ' ' oogone (or carpogone), and that when it was first separated as a distinct cell it was still a fertile part of the archicarp. In Aspergillus repens the terminal cell, or "trichogyne," some- times gives rise to ascogenous hyphae (Fraser, '08). The terminal cell became merely a trichogyne when it ceased to give rise to ascogenous hyphae, and acted as a transport tube for the sperm nuclei from the antheridium to the as- cogonium, as in Pyronema and Monascus. The septum be- tween the terminal cell and the functional ascogonium was an impediment to the passage of the sperm nuclei, as well as the fact that when they entered the terminal cell of the archi- carp they did not meet with functional egg nuclei. This situa- tion very likely favored the assumption of sperm and egg functions by the nuclei of the functional ascogonial cell. The variations in Pyronema where the antheridium may or may [Vol. 2 356 ANNALS OF THE MISSOURI BOTANICAL GARDEN not be present, and often when present and fused with the trichogyne its nuclei degenerate and the ascogonium is still functional producing ascogenous hyphae and asci, is in sup- port of this interpretation. Further sterilization of the terminal portion of the archi- carp proceeds as it becomes longer and more septate, the fer- tile ascogonial cell or cells being near the center or base. All of the sterile portion of the archicarp distal to the ascogonial cells is usually interpreted as the trichogyne. I believe it would be more in harmony with the historical origin of the archicarp, and with the real homologies, if only the terminal sterile receptive cell of the archicarp were called the trich- ogyne, the other portions to be regarded as sterile portions of the archicarp or ascogonium. This would be in harmony also with Thaxter's ('96) interpretation of the archicarp of the L ab o alb eni ales. 1 In this group the inferior and superior sup- porting cells are sterile cells of the archicarp derived by a transverse splitting of the ascogonium. Even with this inter- pretation of the trichogyne of the Ascomycetes, it would be a different structure from that of all the red algae where it is merely a continuous prolongation of the egg cell. NOTE VI The coenocytic character of the mycelium of the Phycomy- cetes has been presented as an obstacle to the derivation of the sac fungi from the sporangium fungi (Bessey, E. A., '13) ; this character can, however, have very little or no significance, for many of the Ascomycetes are coenocytic. As in most of the fungi, cell wall formation is delayed so that new portions of filaments are often multinucleate, the cell walls being laid down subsequently, sometimes enclosing one nucleus, some- times several in a cell. There are the monoenergid and poly- energid species of sac fungi. In the Phycomycetes cell wall formation is usually longer delayed or does not occur except where reproductive cells are formed. In the Muco rales old mycelium frequently becomes multiseptate. It should be noted that in Basidiobolus (Eidam, '86; Raciborski, '96; Fair- 1 Except in the case of the multiseptate branched triohogynes. 1915] ATKINSON PHYLOGENY IN THE ASCOMYCETES 357 child, '97, and others) the cells are uninucleate. The varia- tion in coenocytic character of mycelium probably is due in some measure to the usually fundamental difference between cross wall formation in dividing cells, in the thallophytes and the higher groups of plants, where the fibers of the inner spindle play a part and the cell wall development is centrif- ugal, while in most thallophytes the spindle fibers do not play such a part, wall formation being centripetal, like a clos- ing iris diaphragm. The strong plasma connections between the protoplasts of the Laboulbeniales (Thaxter, '96) present a very striking re- semblance to those in the red algae. This feature is regarded by some as very strong evidence of a phylogenetic relation between the Laboulbeniales and the red algae. But intercellu- lar plasma connections are a common feature in all groups of plants, though in many plants these connections are very minute. The single central pore in the wall of the Laboul- beniales is perhaps the result of incomplete closing of the ring- forming wall, and in the Laboulbeniales would seem to be of physiological rather than of phylogenetic significance. The firm cell walls which are characteristic of the members of this group bear a very definite relation to their habit as external parasites of insects. Standing out free from their bodies and thus having no other means of support than their own rigidity, thick cross walls would interfere with transport of food ma- terial, while the prominent plasma connections permit easy passage of nutrients. NOTE VII BRIEF OUTLINE OF SOME OF THE THEORIES AS TO THE PHYLOGENY OF THE ASCOMYCETES I. Descent from the Rhodophyceae. — Sachs ( 74, p. 287) regarded the resemblances between cystocarp and ascocarp as the most important character indicating a relationship be- tween the red algae and sac fungi, although the form of the sexual organs, particularly the carpogonial branch, was also believed to point in the same direction. In his ' Lehrbuch der Botanik' he did not even suggest that the Ascomycetes were derived from the Florideae. The relationships were based 358 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 on the principle of morphological homology, which he believed were great enough to justify their inclusion in the same class. To justify his arrangement in one large group of plants with such diverse aspects and habilats, he cites the inclusion of the Lemnaceae and palms in the great group of the monocots. We could not then interpret his inclusion of the sac fungi and red algae in one class, the Carposporeae, as indicating that the former w T ere derived from the latter. Sachs says ( 74, p. 288) that in order to find the relation- ships between plant divisions one must compare the simplest, not the highest forms. By this method he finds that the Coleochaetaceae and Characeae are linked, on one hand to the simplest Florideae, and on the other to the simplest As- comycetes. Each of these series, he says, has developed in its own peculiar manner to higher forms, so that if one com- pared the most complete Ascomycetes with the coleochaetes only very slight resemblances are to be found. From this it is very clear that Sachs, at that time, had no thought of the derivation of the Ascomycetes from the Florideae. There is nothing to indicate that he believed the Ascomycetes descended from the charas and simplest coleochaetes, to which he says the simplest Ascomycetes are most closely related. Nor would his theory require a common ancestor for the two groups. Because of the morphological resemblance between cystocarp and ascocarp, he would have united the Ascomy- cetes and Florideae into a higher group even had he believed that the former were derived from the Phy corny cetes. It has been said by Sachs ( '96, p. 204) that the fungi as a whole cannot be valued as an architype because, as apochlo- rates, they must be descended from green plants. The bacteria he would derive from the Cyanophyceae, the Phycomycetes from the Siphoneae, and the Ascomycetes (or at least the Discomy cetes) from the Rhodophyceae. The predominant feature indicating the descent of the sac fungi from the red algae he now sees in the procarp of both groups ( '96, p. 205). The chlorophylless seed plants have only a slight form-pro- ducing power or motive, as Sachs has pointed out ( '96, p. 205), since they occur mostly as small plant groups within certain 1915] ATKINSON PHYLOGENY IN THE ASCOMYCETES 359 ii leaved families and show very plainly the morpholog- characters of their antecedents. But he says it is quite , The simplest primitive forms of otherwise with the fung the Ascomvcetes, Phycomycetes and Basidiom have given rise independently to an enormously high state of dif fe Now Sachs in 1896 (and 74 310) recognized Gymnoascus as belonging to the simplest A pollinode. the Ascom o ___ f which are a simple carpogone and It is very clear then that Sachs would not derive fcetes from any primitive form at all like any known red algae, much less through such forms as the highly pecialized Collema or Polystigm This eluding that Sachs had in mind a primitive hypothetical an- cestor of the sac fungi and red algae, which possessed simple copulating gametes. With the knowledge we possess to-day of such forms as Dipodascus, Eremascus, etc., where the zygote becomes the ascus (generalized or simple) I believe he would have recognized in the Phycomycetes, as we know them to-day, a situation very closely approximating an "Urform" for the Ascomvcetes, particularly in view of the fundamental difference in the of the red algae and sac fungi But whether the fungi represent one or several architypes it by no means follows that, because of the absence of chloro- phyll, they must be derived from green plants, or that each great series must be derived separately from different groups of The appearance of the higher fungi (Eumycetes) was, in the opinion of Vuillemin ('12, p. 223), contemporaneous with the emergence of sea-shore, which abandoned certain red algae terrestrial life. This new environment introduced the to change, which, accompanied by loss of chlorophyll first to the Pyrenomycetes, from which the other higher fungi The sapro- Uredinal Basidiomi have ginated phytic forms represent the productive and progressive stock Parasitic groups, like the Uredinales, Laboulbeniales, lichens etc., are composed of highly specialized and uniform members their progressive potentialities being suppressed, but they re tain their hold on existence because of their specialized hab [Vol. 2 360 ANNALS OF THE MISSOURI BOTANICAL GARDEN itat. The first Pyrenomycetes, according to his view, were some of these depatriated red algae, losing their pigments while preserving the structure, the sexual organs and the gen- eral evolution. But he recognized no known member of the red algae as a prototype of the Pyrenomycetes. Primitive trichogyne-bearing algae gave rise to the red algae on one hand, and to the Pyrenomycetes on the other, the now known colorless red algae (like Uarveyella mirabilis, Choreocolax alba) being recently reduced forms having no significance in the origin of the sac fungi. But the Pyrenomycetes with well developed trichogyne and spermatia are chosen as the primi- tive forms, the simplest represented by Polystiyma (in his "Polystigmales") the higher ones (his "Pyreniales") giving rise successively to the llysteriales and Phacidiales. From the Polystiy males three other lines arose, their simplest forms being represented by first, Gymnoascus; second, Pyronema; and the third line represented by the Laboulbeniales (see Vuillemin, '12, pp. 338-341). Bessey ( 14) regards the Discolichenes as the most primi- tive Ascomycetes. This theory is based on the supposed phyletic relation of the multiseptate trichogyne of the lichens (Collema, for example) to the trichogyne (a mere tubular, continuous, prolongation of the egg) of the red algae. Cer- tain of the red algae became parasitic on blue-green algae and on simple members of the green algae, forming a lichen thallus. It is supposed that this parasitism may have had its origin while both kinds of organisms still lived in the water, but finally the lichen assumed the land habit. The improba- bility of such a derivation of the sac fungi as suggested in the above theories has been fully discussed in the preceding pages. II. Descent f -De Bary ( '81, '84, '87), as already stated in the first part of this paper, be lieved the Ascomycetes were derived from the Phy corny cetes, particularly through such forms as the Peronosporales. The criterion for the relationship is the close homology and mor- phological resemblance of the sexual organs, though he sug- gested that Eremascus might have been derived from the Mucorales through some such form as Piptocephalus where 1915] ATKINSON — PHYLOGENY IN THE ASCOMYCETES 361 the zygote is the outgrowth from the fusion point of two equal gametangia. Brefeld ('89, '91) also derived the Ascomycetes from the Phycomycetes but interpreted the ascus as the phyletic hom- ologue of the sporangium, the ascus representing a special- ized structure derived from the generalized sporangium in one direction, while the conidia were regarded as reduced one- spored sporangia. But the nuclear fusion and reduction phenomena in the ascus are so fundamentally different from any known cytological processes in the sporangium, that its phyletic relation to the sporangium is doubtful. 1 The con- jugation of the gametangia he interpreted as ordinary fusion of hyphae which occurs in numerous instances devoid of all sexual significance. Protomyces, Ascoidea and Thelebolus, with numerous spores in the ascus, were interpreted as rep- resenting an intermediate condition between the generalized sporangium of the Mucorales and the specialized ascus. In Thelebolus it has been found that the development of the ascus follows the type with crozier formation and that it is closely related to Ascobolus and Rhyparobius (see Ramlow, '06; Dangeard, '07). As for Protomyces and Ascoidea they prob- ably represent forms with reduced sexuality while retaining the ancestral character of many divisions of nuclei to form numerous spores. Zukal ('89), influenced by Brefeld, derived the hymenial Ascomycetes (like Ascobolus, Pezizales, etc.) through Thele- bolus and Monascus; the stromatic Ascomycetes (whether Pyrenomy cetes or Discomycetes) from the Uredinales; the Gymnoascales and others with asci arising directly from the mycelium, from another ancestral type. Lotsy ( '07, p. 469) sees no difficulty in deriving the polyener- gid forms like Pyronema from the Phycomycetes. The forms with spermatia, which are usually monoenergid, it would seem rational, he thinks, to derive from the red algae, and this raises the question as to whether the Ascomycetes are of poly- phyletic (or biphyletic) origin. The great uniformity of the x The nuclear phenomena in the "germ" sporangium (from the zygote) are not known. 362 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 ascus in the entire group is a great obstacle in the way of accepting a polyphyletic origin for the group. All things con- sidered he is inclined to accept de Bary's view of their phy- comycetous origin. The origin of the Ascomycetes from the Phy corny cetes is recognized by Dangeard ('07) through such forms in which there is still a union of gametangia. Dipodascus and Ere- mascus represent such forms in his scheme. The generalized ascus resulting from the union of the gametangia of Dipo- dascus he terms a "sporogone." From Eremascus, by re- duction, forms like Endomyces arose, while the Ascomycetes with ascogenous hyphae were derived from such forms as Dipodascus by delayed nuclear fusion and the proliferation of the gametangium into what he terms "gametophores" (= as- cogenous hyphae). The gametes then are formed in the nuclear pair which fuses in the ascus. This terminology arises from his persistent belief that the ascus is the egg. Shorn of the change in terminology and his, perhaps, unfor- tunate insistence on homologizing the ascus with the egg, his interpretation of the relation which such a form as Dipodascus bears to the Ascomycetes, has much merit. Nienburg ( '14) suggests the origin of the Ascomycetes from the Phycomycetes through some such form as Monoblepharis. He would find the evidence for this in the homology of the archicarp of Polystigma rubrum with such forms of Monoble- pharis in which the stalk cell of the oogonium is an anther- idium, and where the oogonium is terminated by one or more sterile cells. The archicarp of Polystigma he interprets as having two fertile cells at the base and prolonged into a long sterile septate portion (so-called trichogyno) which forks, sending a branch to either surface of the leaf. The basal multinucleate cell is the antheridium. After pore formation one nucleus migrates into the unicellular eerer. Interesting as ^ Atkins forms of Pythium (see de Bary, '81, '84; l intercalary oogonia and stalk antheridia lalogy to the archicarp of Polystigma as described by Nienburg, but it is extremely doubtful if point of contact is to be sought through such structures. 1915] ATKINSON PHYLOGENY IN THE ASCOMYCETES 363 comparative summary the b views on the phytogeny the A The adherents to the doc of the red algal origin of the Ascomycetes interpret the of contact in three different ways : first, sac fungi with highly developed (sterilized archicarp) of the Collema tvDe with red aljrae like certain of the existing forms Nemalion. or some of the higher forms veyella, etc. ; second sac fnng with highly ;y of Har- developed trichogy sterilized archicarp) of the Poly stigma type with hypothetical trichogyne algae representing the com- mon stock for the origin of both groups ; third, sac fungi with simple generalized copulating gametes of the Gymnoascus type with hypothetical algae having a simple procarp repre- & the stock from which both .-> According to the two fi interpretat ginated. the sac fung have been derived through highly developed and specialized forms from either quite highly developed and specialized red algae, or both groups from a common trichogyne algal stock, and then by degeneration have slid backward from complex and specialized structures to simple, generalized and primi- tive ones. The third view which recognizes a simple procarp, without regard to a trichogyne, as the important character of the hypothetical stock, is far more comprehensible. But if we must go back to some hypothetical ancestor, which cannot be represented by any known red alga, for the source of the sac funeri it is far more reasonable to search for one & m another fungus line, where, in arc known forms the light of day ledge, there much like the sexual organs of simple, known forms of the A But we are not vet in a position to name known phycomycete 1 as a probable ancestor of the A cetes, though it appears very likely that the ancestral stock possessed phycomycetous characters. x Lotsy ('07) suggests Cystopus; Miss Dale ('03) in her study of Gymnoascus suggests Basidiobolus; Nienburg ('14), Monoblepharis; while Dangeard ('07) suggests Myzocytium vermicolum as the prototype of the higher fungi. [Vol. 2 364 ANNALS OF THE MISSOURI BOTANICAL GARDEN PROVISIONAL ARRANGEMENT OF MAIN LINES OF DEVELOPMENT IN ASCOMYCETES For those who are interested in the suggestions as to the phylogeny and relationships of the Ascomycetes presented in this paper, a diagrammatic arrangement of the principal series or lines which will illustrate the relationships tenta- tively held by the writer may be acceptable. It is with con- siderable hesitation that this arrangement is presented. The writer trusts that it will be accepted as provisional and in the nature of a working hypothesis which he hopes will fur- ther stimulate investigation, suggestions and criticisms on the ideas embodied in this paper, all of which, for or against, will be gladly welcomed. Dipodascus, a primitive form, cells of mycelium polyen- ergid, gametogenous branches large, unequal, polyenergid. Ascus is elongated, broadened zygospore, zygote germinating immediately forming a broad germ tube in which spores are formed. Since the process does not go on to the formation of a sporangium, a different mode of internal free cell-forma- tion then arose in connection with the precocious formation of spores in the zygote and retention of epiplasm which assists in discharge of spores. Dipodascus retains tendency of gamogenic branches to copulate early before they become strongly differentiated as gametangia, just as in Mucorales. I. Protoascomycetes are derived by descent and degenera- tion from some such primitive ascomycete form as Dipodascus. The ascus when of sexual origin is the zygote, except in Nad- sonia. Endomyces Magnusii is the nearest known form to the gen- eralized condition seen in Dipodascus. Cells of mycelium usually polyenergid, those of stout mycelium are polyenergid. Formation of ascus in Endomyces Magnusii repeats formation of zygospore in Zygorhynchus. Gamete branches in both are multinucleate, but when cell wall is laid down delimiting the gametangia all but one nucleus in each gametangium of E. Magnusii are excluded. After contact of the two sexual branches the male gametangium is formed by enlargement of its tip, into which protoplasm and the one nucleus migrates, 1915] ATKINSON — PHYLOGENY IN THE ASCOMYCETES 365 exactly as male gamete of Zygorhynchus is formed, except the latter is multinucleate. By disappearance of the separating wall, ascus is formed of the two gametes. Endomyces series, then, derived from Dipodascus-like an- cestors, with Endomyces Magnusii the lowest and most gen- eralized. Developmental tendencies from here in four, five, or six different directions : l.Eremascus, both gamogenic branches uninucleate, ascus more definite and specialized in shape. Loss of conidial formation. Endomyces fibuliger indicates step toward Eremascus (E. fer- tilis) in small size of gametes. 2. Endomyces diverging into the two series, one chiefly with sprout conidia, the other chiefly with oidia; the latter preserves the E. Magnusii character, the former takes on sprout conidia in addi- tion to oidia (E. fibuliger and E. capsularis form both oidia and sprout conidia) ; oidia formation the more primitive and gener- alized condition in Ascomycetes. 3 m more specialized and reduced Endomyces fibuliger and in this same line. Schizosaccharomyces may have come from same line with dropping of sprout conidia, or may be descended from form near Endomyces Magnusii. 4. Exoascaceae. From En nomena not well known. formation ancestors. Nuclear phe- ng ascus may have arisen in ascogone instead of one as in E. Magnusii, where all but one are excluded at time of wall formation, i. e., ascus fundament may have retained the polyenergid character of the most primi- forms like E. Magnusii mature form hymenia may Taphrina laurencia, 5. Ascocorticium, saprophytic on wood where food is not so rich, tendency to drop conidial formation (?), association of asci in hymenium, highest development of the Endomyces series, or of the Protoascomycetes. Series is terminated early, tendency in Endomyces line to specialization of zygote into one ascus with reduced number of spores, and line soon terminated. 6. Ascoidea, Protomyces, Taphridium, etc., pro bably represent forms derived by reduction and loss of distinct sexual organs but preserving primitive feature of many divisions of nucleus in the generalized ascus. II. Euascomycetes. Lowest forms with generalized archi- carp Similar to Monascus, Gymnoascus, etc. [Vol. 2 366 ANNALS OF THE MISSOURI BOTANICAL GARDEN 1. Tendency to late copulation of gamogenic branches, so that archicarp becomes large and many-nucleate, or tendency to elongate, or both. 2. As it elongates tendency to septation, first a single terminal cell ("trichogyne"), and later longer and multiseptate "trichogyne," or rather sterilization of terminal portion of archicarp. One of the early tendencies in connection with elongation of the archi- carp may have been the origin of a receptive terminal portion under chemotactic or similar stimulation ; such a condition sug- gested in Cystopus. 3. This made the passage of antheridial nuclei increasingly diffi- cult, and resulted in early tendency to sterilization of anther- idium or failure to function because of functionless condition of "trichogyne." Led in many cases to modified sexuality by dif- ferentiation of sex among nuclei in ascogonium, vegetative cells, or ascogenous threads. 4. Progressive tendency to multiplication of spores by postpone- ment of nuclear fusion and spore formation; conjugate division of sex nuclei, and multiplication of the specialized structures (asci) in which spores are formed, so that spore formation and distribution is extended over greater period of time. This most advantageously attained by sprouting of zygote (ascogone), branching of threads, and terminal formation of specialized asci. Diverging lines from Gymnoascus and Monascus -like an- cestors or related prototypes in which asci are irregularly arranged but associated in groups with imperfect envelope. 1. A line with interwoven asci, Plectascales as a highly specialized lateral group, with Gymnoascaceae at base. Aspergillaceae a progressive line, with Perisporiales an offshoot, or Perisporiales direct from Monascus-like ancestors. 2. Elaphomycetaceae, asci interwoven in groups but separated by sterile walls. 3. Pezizales, asci remaining in groups not interwoven in mycelium, but spaced by sterile threads (paraphyses). Pyronema repre- sents one of the generalized, lower forms. The Helvellales, etc., are probably derived from the Pezizales. 4. The Microthyriales 1 have usually been placed among the Peri- sporiales with which they have little in common. I believe they 1 Recent studies by several authors, particularly by von Hohnel ('10) and by Theissen ('12, '13, '14) have greatly increased our knowledge of these interest- ing fungi, partly by the discovery of new forms but especially by uncovering many forms from the clouded situation in which they have been placed for lack of an adequate study of their structure. 1915] ATKINSON PHYLOGENY IN THE ASCOMYCETES 367 represent reduced forms derived on the one hand from the Pha- cidiales and perhaps on the other from the Sphaeriales and pos- sibly some from the Perisporiales. The formation of the char- acteristic shield has rendered superfluous the perithecial wall as a protective structure. The genus Diplocarpon, the structure and development of which was investigated by one of my former students (see Wolf, '12), I believe is an excellent illustration of a form on the way (by reduction of the perithecial wall in con- junction with the formation of the shield) from the Phacidiales to the condition presented by many members of the Micro- thyriales. The above provisionally suggested relationships may be represented by the following five or six series, or lines of development, with the accompanying diagram (fig. 10) : 1. Apocarp line from Dipodasc us-like forms and by reduction. 2. Plectocarp line from Dipodascus-like forms, perhaps similar to Monascus. 3. Perispore line arising from Monascus-like prototype, before splitting of archicarp, or from Aspergillaceae. 4. Pyrenocarp line arising near Monascus-like prototype. Laboul- beniales side line near base, and some of the Mycrothyriales as reduced from Sphaeriales. 5. Discocarp line from Dipodascus-like forms near Monascus, but lower (it is not improbable that some of the members of the stock of primitive Euascomy- cetes showed considerable variation in the strength of the ascocarp envelope, also in its presence or absence in forms where it is more or less rudimentary 1 ) ; and some of the Microthy- riales as reduced forms from Phacidiales. Or a 6th line also, Laboulbeniales from Monascus-like ancestor. 1 This variation sometimes occurs in existing forms. Zukal ('89) describes an abnormal case in Eurotium (Aspergillus) herbariorum where the antheridial branch and envelope are wanting, the mass of asci being exposed. In this con- nection it is worthy of note that Fraser and Chambers ('07) regard Aspergillus "as representing a primitive aseomycetous type from which most others can be derived." This suggestion was based on the assumption that the red algae were the ancestors of the sac fungi. On the basis of the counter theory (phyco- mycetous origin) Gymnoascns and Monascus-like forms are more comprehensible as primitive Euascomycetes. 368 [Vol. 2 ANNALS OF THE MISSOURI BOTANICAL GARDEN Fig. 10. Chart showing suggested phylogeny of the Ascomycetes. Literature Cited Atkinson, Geo. F. ('95). Damping off. Cornell Univ. Agr. Exp. Sta., Bull. 94: 231-272. pi. 1-6. 1895. Bachmann, Miss F. M. ('12). A new type of spermogonium and fertilization in Collema. Ann. Bot. 26:747-760. pi. 69. 1912. , ('13 ). The origin and development of the apothecium in Collema pul- posum (Bernh.) Ach. Archiv f. Zellforsch. 10:309-430. pi. 30-36. 1913. 1915] ATKINSON PHYLOGENY IN THE ASCOMYCETES 369 Barker, B. T. P. ('03). The morphology and developm Monascus. Ann. Bot. 17:107-230. pi. 12-13. 1903. de , ('04). Further observations on the ascocarp of Rhyparobius. British Assoc. Adv. Sci., Cambridge, Rept. 1904: 825-826. 1905. Bary, A. ('81). Untersuchungen iiber die Peronosporeen und Saprolegnieen und die Grundlagen eines natiirlichen Systems der Pilze. In de Bary und Woronin, Beitr. z. Morph. u. Physiol, d. Pilze 4: 1-145. pi. 1-6. 1881. ('84). Vergleichende Morphologie und Biologie der Pilze, usw. Leipzig, 1884. — , ('87). Comparative Morphology and Biology of and Bacteria. 1887. Baur, E. ('98). Zur Frage nach der Sexualitat der Collemaceen. Ber. d. deut bot. Ges. 16:363-307. pi. 23. 1898. — — ♦ — , ( '04 ) , Untersuchungen iiber die Entwickelungsgeschichte der Flechten apothecien. Bot. Zeit. 62:21-44. pi. 1-2. f. 1. 1904. Bessey, C. E. ('14). Revisions of some plant phyla. Univ. Neb. Stud. 14: 37-109 1914. Bessey, E. A. ('13). Some suggestions as to the phylogeny of the Ascomycetes. Myc. Centralbl. 3: 149-153. 1913. Blackman, V. H. ('98). phenomena in Pinus 395-427. pi. 13-1/,. On the cytological features of fertilization and related sylvestris L. Roy. Soc. London, Bot., Phil. Trans. 190: 1898. , ('04). On the fertilization, alternation of generations and general cytology of the Uredineae. New Phytol. 3:23-28. 1904. , ('04). On the fertilization, alternation of generations and general cytology of the Uredineae. Ann. Bot. 18:323-373. pi. 21-24. 1904. , and Fraser, H. C. I. ('05). Fertilization in Sphaerotheca. Ann. Bot. 19:567-569. 1905. , , ('06) . On the sexuality and development of the ascocarp of Humaria granulata Quel. Roy. Soc. London, Bot., Proc. 77:354-368. pi. 13-15. 1906. , f ('06). Further studies on the sexuality of the Uredineae Ibid. 20: 35-48. pi. 3-4. 1906. , and Welsford, E. J. ('12). The development of the perithecium of Poly stigma rubrum DC. Ann. Bot. 26: 761-767. pi. 70-71. 1912. Boveri, Th. ('88). Zellen Studien II. Die Befruchtung und Zellteilung des Eies von Ascaris megalocephala. Jena, 1888. Brefeld, 0. ('88). Basidiomyceten II. Protobasidiomyceten. Untersuchungen aus dem Gesammtgebiete der Mykologie 7: IX and 1-178. pi. 1-11. 1888. — — , ('89). Basidiomyceten III. Autobasidiomvceten und die Begriindung des natiirlichen Systemes der Pilze. Ibid. 8: 1-274. pi. 1-11. 1889. ('91). Die Hemiasci und die Ascomyceten. Ibid. 9:1-156. pi. 1-3B. 1891. ('91). Ascomyceten II. Ibid. 10:157-378. pi. 4-13. 1891. Brooks, F. T. ('10). The development of Gnomonia erythrostoma Pers. Ann. Bot 24: 585-605. pi. 48-4$. 1910. 370 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 Brown, H. B. ('13 ). Studies in the development of Xylaria. Ann. Myc, 11: 1-13. pi. 1-2. 1913. Brown, W. H. ('00). Nuclear phenomena in Pvronema conlluens. Preliminary note. Johns Hopkins Univ. Circ. N. S. 28": 42-45 (1-6). f. 1-3. 1909. , ('10). The development of the ascocarp of Leotia. Bot. Gaz. 50:443- 459. f. 1-47. 1910. , ('11 ). The development of the ascocarp of Lachnea scutellata. Ibid. 52:273-305. pi. 9. /. 1-51. 1911. Carruthers, C. ('11). Contributions to the cytology of Helvella crispa. Ann. Bot. 25 1 : 243-252. pi. 18-19. 1911. Chmielewski, W. F. ('90). Materiaux pour servir & la morphologie et physiologic des proems sexuels chez lea plantes inferieurs. 1890. Chodat, R. ('10). Etudes, sur les Conjugees 1. Sur la copulation d'un Spirogyra. Soc. Bot. Geneve, Bull. II. 2: 158-107- f. «-g. 1910. Christman, A. H. ('05). Sexual reproduction in the rusts. Bot. Gaz. 39: 207-275. pi. 8. 1905. , ('07). The nature and development of the primary uredospore. Wis. Acad. Sci., Trans. 15: 517-520. pi. 29. 1907. Claussen, P. ('05). Zur Entwicklungsgeschichte der Ascomyceten. Boudiera. Bot. Zeit. 63: 1-28. pi. 1-3. f. 1-6. 1905. , ('07). Zur Kenntnis der Kernverhiiltnisse von Pyronema conlluens. Ber. d. deut. bot. Ges. 25:580-590. f. 1. 1907. , ('08). Ueber Eientwicklung und Befruchtung bei Saprolegnia. Ibid. 26: 144-101. pi. 6-7. 1908. , ('12). Zur Hntwickelungsgeschichte der Ascomyceten. Pyronema con- lluens. Zeitschr. f. Bot. 4: 1-04. pi. 1-6. f. 1-10. 1912. Cutting, E. M. ('09). On the sexuality and development of the ascocarp in Asco phanus carneus Pers. Ann. Bot. 23:399-417. pi, 28. 1909. Dale, Miss E. ('03). Observations on the Gymnoasceae. Ann. Bot. 17*571-596 pi. 27-28. 1903. , ('09). On the morphology and cytology of Aspergillus repens. Ann Myc. 7:215-225. v l. 2-3. 1909. Dangeard, P. A. ( 9 92). Recherches sur la reproduction sexuelle des champignons Le Botaniste 3: 222-2S1. pi. 20-23. 1892. , ('94). La reproduction sexuelle des Ascomycetes. Ibid, 4:21-58. f 1-10. 1894. , ('97). La reproduction sexuelle des Ascomycetes. Ibid. 5:245-284 f. 1-11. 1897. , ('07). Recherches sur le dSveloppement du p£rithece chez les Ascomj cetes. Ibid. 10: 1-385. pi. 1-91. 1907. Darhishire, O. V. ('00). Uber die Apothecienentwickelung der Fleehte Physcia pulverulenta (Schreb.) Nyl. Jahrb. f. wiss. Bot. 34:329-345. pi. 11. 1900. Davis, B. M. ('90). The fertilization of Batrachospermum. Ann. Bot. 10:49-76. pi. 6-7. 1890. ■ , ('03). Oogenesis in Saprolegnia. Bot. Gaz. 35:233-249, 320-349. pi. 9-10. 1903. 1915] ATKINSON PHYLOGENY IN THE ASCOMYCETES 371 Dodge, B. O. ('12 ). Artificial cultures of Ascobolus and Aleuria. Mycologia 4:218-222. pi. 12-13. 1912. , ('12a). certain species 10-15. f. 1-2. Methods of culture and the morphology of the of the Ascobolaceae. Bull. Torr. Bot. Club 39 1912. archicarp in 139-197. pi. ('14). The morphological relationships of the Florideae and the Ascomycetes. Ibid. 41: 157-202. f. 1-13. 1914. Eidam, E. ('80). Beitrag zur Kenntniss der Gymnoasceen. Beitr. z. Biol. d. Pfl. 3:2G7-305. pi 12-15. 1880. — , ('83). Zur Kenntniss der Entwicklung bei den Ascomyceten. Ibid. 3:376-433. pi 19-23. 1883. , ('86). Basidiobolus, eine neue Gattung der Entomophthoraceen. Ibid. 4: 181-251. pi. 9-12. 1880. Fairchild, D. G. ('97). Ueber Kerntheilung und Befruchtung bei Basidiobolus ranarum Eidam. Jahrb. f. wiss. Bot. 30:285-296. pi 13-14. 1897. Faull, J. H. ('05). Development of ascus and spore formation in Ascomycetes. Boston Soc. Nat. Hist., Proc. 32: 77-113. pi 1-11. 1905. ('11). The cytology of the Laboulbeniales. Ann. Bot. 25:649-654. 1911. — , ('12). The cytology of Laboulbenia chaetophora and L. Gyrinidarum. Ann. Bot. 26:325-353. pi 31-40. 1912. Ferguson, Margaret C. ('01). The development of the egg and fertilization in Pinus Strobus. Ann. Bot. 15:435-479. pi 22-25. 1901. ■, ('04) . Contributions to the knowledge of the life history of Pinus with special reference to sporogenesis, the development of the gametophytes and fertilization. Washington Acad. Sci., Proc. 6: 1-202. pi 1-24* 1904. Fisch, C. ('82). Beitrage zur Entwickelungsgeschichte einiger Ascomyceten. Bot. Zeit. 40: 851-905. pi 10-11. 1882. Frank, A. B. ('83). Ueber einige neue und weniger bekannte Pflanzenkrankheiten. II. Polystigma rubrum. Ber. d. deut. bot. Ges. 1:58-62. 1883. — » — ■ , ('86). Ueber Gnomonia erythrostoma, die Ursache einer jetzt herr- schenden Blattkrankheit der Siisskirschen im Altenlande, nebst Bemerkungen liber Infection bei blattbewohnenden Ascomyceten der Baume uberhaupt. (Vorlaufige Mittheilung. ) Ibid. 4:200-205. 1886. Fraser, Miss H. C. I. ('07). On the sexuality and development of the ascocarp in Lachnea stercorea. Ann. Bot. 21:349-360. 1907. , ('08). Contributions to the cytology of Humaria rutilans Fries. Ann. Bot. 22:35-55. pi 4-5. 1908. , ('13). The development of the ascocarp in Lachnea cretea. Ibid. 27: 553-563. pi. 42-43. 1913. , and Brooks, W. E. St. John ('09). Further studies on the cytology of the ascus. Ibid. 23:537-549. pi 34~40. f. 1. 1909. , and Chambers, H. S. ('07) . The morphology of Aspergillus herbariorum. Ann. Myo. 5: 419-431. pi 11-12. 1907. , and Welsford, E. J. ("08). Further contributions to the cytology of the Ascomycetes. Ann. Bot. 22:465-477. pi 26-21. 1908. [Vol. 2 372 ANNALS OF THE MISSOURI BOTANICAL GARDEN Gates, R. R. ('09). The stature and chromosomes of Oenothera gigas De Vries. Archiv. f. Zellforsch. 3:526-652. 1909. >, ('13). Tetraploid mutants and chromosome mechanisms. Biol. Cen- tralbl. 33: 92-150. f. 1-7. 1913. Guilliermond, A. ('08). La question de la sexuality chez lefl Ascomyoetes. Rev Gen. Bot. 20:32-39, 85-89, 111-120, 178-182, 298-305, 333-334, 304-377 f. 1-86. 1908. , ('09). Recherches cytologiques et taxonomiques sur les Endomycet^es Ibid. 21:354-391, 401-419. pi. 13-19. 1909. •, ('12). Les levures. 1-505. f. 1-163. Paris, 1912. Harper, R. A. ('95). Beitrag zur Kenntniss der Kern thei lung und Sporenbildung im Ascus. Ber. d. deut. bot. Ges. 13: (67)- (68). pi. 27. 1895. ■, ('95a). Die Entwickelung des Peritheciums bei Sphaerotheca Castagnei. Ibid. 13:475-481. pi. 89. 1895. •, ('96). Ueber das Verhalten der Kerne bei der Fruchtentwickclung einiger Ascomyceten. Jahrb. f. wiss. Bot. 29:055-685. pi. 11-12. 1896. , ('99). Cell-division in sporangia and asci. Ann. Bot. 13:467-525. /)/. 24-26. 1899. , ('00). Sexual reproduction in Pvronema conlluens and the morphology of the ascocarp. Ann. Bot. 14:321-400. pi. 19-21. 1900. , ('02). Binuclcate cells in certain Hymenomycetes. Bot. Gaz. 33: 1-35. pi. 1. 1902. ' — ' — , ('05). Sexual reproduction and the organization of the nucleus in certain mildews. Carnegie Inst. Washington, Publ. 37: 1-104. pi. 1-7. 1905. Kartog, M. M. ('95). On the cytology of the vegetative and reproductive organs of the Saprolegnieae. Roy. Irish Acad., Trans. 30:649-708. pi. 88-29. 1895. Hoffmann, A. W. H. ('12). Zur Entwicklungsgeschichte von Endophyllum sem- pervivi. Centralbl. f. Bakt. II. 32: 137-158. pi. 1-2. f. 1-1^. 1912. von llohnel, F. ('10). Fragmente zur Mykologie. X. Mitteilung. K. Akad. Wiss. Wien., Math.- naturw. Kl., Sitzungsber. 119:393-473 (1-81). f. 1. 1910. Janczewski, E. (71). Morphologische Untersuchungcn ilber Ascobolus furfur- aceus. Bot. Zeit. 29:257-262, 271-278. pi. J h 1871. Juel, H. O. ('02). Taphridium Lagerh. & Juel. Eine neue Cattung der Protomy- cetaceen. Bihang K. Bv. Vet.- Akad. Handl. 27 16 :Afd. III. 1-29. pi. 1. 1902. — , ('02). Uber Zellinhalt, Befruchtung und Sporenbildung bei Dipodascus. Flora 91:47-55. pi. 7-8. 1902. Karsten, G. (•'OS). Die Entwicklung der Zygoten von Spirogyra jugalis Ktzg. Flora 99: 1-11. pi 1. 1908. Kihlman, O. ('83). Zur Entwickelungsgeschichte der Ascomyceten. Soc. Sci. Fen- nicae, Acta 13: 1-43. pi. 1-2. 1883. Kniep, H. ('13). Beitriige zur Kenntnis der Hymenomyceten, I, II. Zeitschr. f. Bot. 5:593-637. pi. 2-5. f. 1. 1913. Kurssanow, L. ('11). Ueber Befruchtung, Reifung und Keimung bei Zygnema. Flora 104: 65-84. pi. 1-J,. 1911. Lagerheim, G. de ('92). Dipodascus albidus. eine neue, geschlechtliche Hemiascee. Jahrb. f. wiss. Bot. 24:549-565. pi. 2J,-26. 1892. 1915] ATKINSON PHYLOGENY IN THE ASCOMYCETES 373 Lindau, G. ('88). Ueber die Anlage und Entwicklung einiger Flechtenapothecien. Flora 71: 451-489. pi. 10. 1888. , ('99). Beitrage zur Kcnntniss der Gattung Gyrophora. Festschrift fiir Schwendener. Berlin, 1899. Lotsy, J. P. ('07). Vortrage iiber botanische Stammesgeschichte 1 : 1-IV and 1-828. f. 1-430. 1907. Maire, R. ('99). Sur les ph^nomknes cytologiques pr£c6dant et accompagnant la formation de la tSleutospore chez le Puccinia Liliacearum Duby. Compt. rend. acad. Paris 129: 839-841. 1899. — — , ('01). L'evolution nucleaire chez les Ur£din6es et la sexuality. Bull. Soc. Myc. 17:88-96. 1901. ', ('02). Recherches cytologiques & taxonomiques sur les Basidiomycetes. Ibid. 18:1-209. pi. 1-8. 1902. , ( '03 ) . Recherches cylotogiques sur le Galactinia succosa. Compt. rend. acad. Paris 137:769-771. 1903. Myc , ('05). Recherches cytologiques sur quelques Ascomycetes. Ann 3: 123-154. pi. 3-5. 1905. Marchal, El. et Em. ('09). Aposporie et sexuality chez les Mousses. II. acad. Belg. (classes des Sciences) 1909:1249-1288. 1909. Bull , ('11). Ibid. III. Ibid. 1911:750-778. f. 1-19. 1911. McCubbin, W. A. ('10). Development of the Helvellineae. I. Helvella elastica. Bot. Gaz. 49: 195-206. pi. 14-16. 1910. Miicke, M. ('08). Zur Kenntnis der Eientwicklung und Befruchtung von Achlya polyandra de Bary. Ber. d. deut. bot. Ges. 26 a : 367-378. pi. 6. 1908. Murrill, W. A. ('00). The development of the archegonium and fertilization in the hemlock spruce (Tsuga canadensis Carr.). Ann. Bot. 14:583-607. pi. 21- 22. 1900. Nichols, M. A. ('96). The morphology and development of certain pyrenomycetous fungi. Bot. Gaz. 22:301-328. pi. 14-16. 1896. Nichols, S. P. ('04). The nature and origin of the binucleated cells in some Basidiomycetes. Wis. Acad. Sci., Trans. 15:30-70. pi. 4-6. 1904. Nienburg, W. ('07). Beitrage zur Entwicklungsgeschichte einiger Flechtena- pothecien. Flora 98: 1-40. pi. 1-7. 1907. , CM). Zur Entwicklungsgeschichte von Polystigma rubrum DC Zeitschr. f. Bot. 6: 369-400. f. 1-17. 1914. Olive, E. W. ('05). The morphology of Monascus pupureus. 1905. Bot. Gaz. 39:59-60. , ('07). Cell and nuclear division in Basidiobolus. Ann. Myc. 5:404 418. pi. 10. 1907. , ('08). Sexual cell fusions and vegetative nuclear divisions in the rusts. Ann. Bot. 22:331-360. pi. 22. 1908. Oltmanns, F. ('98). Zur Entwicklungsgeschichte der Florideen. Bot. Zeit. 56: 99-140. pi. 4-7. 1898. , ('04). Morphologie und Biologie der Algen 1:1-733. f. 1-467. Jena, 1904. Osterhout, W. J. V. ('00). Befruchtung bei Batrachospermum. Flora 87:109- 115. pi. 5. 1900. 374 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 Overton, J. B. ('00). The morphology of the ascocarp and spore-formation in the many-apored aaci of Thecotheus Pelletieri. Bot. Gaz. 42-450-41)2 pi 29-30. 190(). Raciborski, M. C96). Studya Mykologiezne ( Mycologische Studies I. Karyo- kinese bei Basidiobolus ranarum, Abaidia robusta nov. sp., Penicillium Poir- aultii nov. sp., Entyloma Nymphaeae Cunningham). Akad. d. Wiaa., Krakau, Anz. 1896:377-386. 1 pi. 10 f. 1890. Ramlow, G. ('06). Zur Entwicklungsgeschichte von Thelebolua stercoreus Tode. Bot. Zeit 64:85-99. 190(3. , ('14). Beitr&ge zur Entwicklungsgeschichte der Ascoboleen. Myc. Centralbl. 5: 177-198. pi. 1-2. f. 1-20. 1914. Ruhland, W. ('01). Zur Kenntnis der intracellular n Karyogamie bei den Basi diomyceten. Bot. Zeit. 59: 187-200. pi. 7. 1901. Sachs, J. ('08). Lehrbuch der Botanik. 1-032. f. 1-465. Leipzig, 1868. , (74). Ibid. 1874. , ('90). Physiologische Notizen X. Phylogenetische Aphorismen und fiber innere Gestaltungsursachen oder Automorphen. Flora 82* 173-223. 1890. Sappin-Trouffy, M. ('90) . Recherches histologiques sur la famille des Ur6din£es. Le Botaniste 5:59-244. /. 1-10. 1896. Schikorra, W. ('09). Ueber die Entwicklungsgeschichte von Monascus. Zeitschr, f. Bot. 1: 379-410. pi. 2. f. 1-3. 1909. Schmidle, W. ('99). Einigea iiber die Befruchtung, Keiinung und Haai insertion von Batrachospermum. Bot. Zeit. 57:125-13.1. pi. F. 1S99. Schmitz, F. ('79). Ueber die Fruchtbildung der Squaniarieen. Niederrhein. Ges. f. Nat.- u. Heilkunde, Bonn, Sitzungsber. 36:370-377. 1879. > , ('80). Ueber die Zellkerne der Thallophyten, Ibid. 37: 122-132. 1880. , ('83). Untersuchungen iiber die Befruchtung der Florideen. K. Preuss. Akad. Wiss., Berlin, Sitzungsber. 1883: 215-258. pi. 5. 1883. , und Hauptlleisch, P. ('97). Rhodophyceae. In Engler & Prantl, Nat. Pilanzenfam. V: 298-544. f. 102-288. Leipzig, 1897. Stahl, E. ('77). Beitr&ge zur Entwickelungsgeschichte der Flechten. 1-55. pi. 1-4. Leipzig, 1877. Stevens, F. L. ('99). The compound oosphere of Albugo bliti. Bot. Gaz. 28: 149- 170, 225-245. pi. 11-15. 1899. — , ^ ('01). Gametogenesis and fertilization in Allnigo. Bot. Gaz. 32: 77-98, 157-169, 238-201. pi. /-//. f. 1. 1901. Stomps, T. J. ('12). Die Entstehung von Oenothera gigas deVries. Ber. d. deut. bot. Ges. 30: 400-410. 1912. Stoppel, R. ('07). Eremaseus fort ilia nov. spec. Flora 97:333-340. pi. 11-12. f. 1-6. 1907. Strasburger, E. ('00). Uber Reduktionateilung, Spindelbildung, Centrosomen und Cilienbildner im Pilanzenreich. Histolog. Beitr. 6: 125. 1900. , ('04). Uber Reduktionstheilung. K. % preuss. Akad. Wiss. Berlin, phys.- math. Kl., Sitzungsber. 18: 587-015. f. 1-0. 1904 1915] ATKINSON PHYLOGENY IN THE ASCOMYCETES 375 , ('05). Typische und allotypische Kernteilung, Ergebnisse und Eror terungen. Jahrb. f. wiss. Bot. 42: 1—71. 1905. , ('09). Sexuelle und apogame Fortpilanzung bei wiss. Bot. 47: 245-288. pi. 7-10. 1909. Urticaceen. Jahrb. f Thaxter, R. ('96). Contribution toward a monograph of the Laboulbeniaceae. Am. Acad., Mem. 12: 189-429. pi. 1-26. 1890. , ('08). Contribution toward a monograph of the Laboulbeniaceae Ibid. 13:219-469. pi. 28-71. 1908. Theissen, F. ('12). Die Gattung Clypeolela v. Holm. Centralbl. f. Bakt. II. 34: 229-235. 1912. , ('12). Fragmenta brasilica IV nebst Bemerkungen iiber einige andere Asterina-Arten. Ann. Myc. 10: 1-32. f. 1-5. 1912. ('12). Fragmenta brasilica V nebst Besprechungen einiger palaeo tropischer Microthyriaceen. Ann. Myc. 10: 159-204. 1912. , ('13). Lembosia-Studien. Ann. Myc. 11:425-467. pi. 20. 1913. < •, ('13). Hemisphaeriales. (Vorlaugfige Mitteilung.) Ann. Myc. 11 468-4(59. 1913. , ('13). Uber einige Mikrothyriaceen. Ann. Myc. 11:493-511. pi. 21 f. 1-7. 1913. , ('13). Die Gattung Asterina in systematischer Darstellung. K.K zool.-bot. Ges., Wien, Abhandl. III. 7: 1-130. pi. 1-8. 1913. ('13). Zur Revision der Gattungen Mycrothyrium und Seynesia Osterr. bot. Zeitschr. 63:121-131. 1913. , ('14). Trichopeltaceae n. fam. Hemisphaorialium. Centralbl. f. Bakt II. 39:625-640. pi. 1. f. 1-7. 1914. , ( '14 ) . Uber Polystomella, Microcyclus, u. a. Ann. Myc. 12 : 63-75 pi. 6-7. 1914. Treub, M. ('05). L'apogamie de TElatostema acuminatum Brogn. Ann. Jard. Bot Buitenzorg II. 5: 141-152. pi. +-11. 1905. Trondle, A. ('07). Ueber die Kopulation und Keimung von Spirogyra. Bot. Zeit 65*: 187-210. pi. 5. f. 1-13. 1907. Twiss, W. C. ('11). Erythrophyllum delesserioides J. Ag. Univ. Calif. Publ Bot. 4: 159-176. pi. 21-2J h 1911. van Tieghem, Ph. ('84). Culture et d^veloppement du Pyronema confluens. Soc Bot. France, Bull. 31: 355-360. 1884. De Vries, H. ('03). Die Mutations-Theorie 1:I-XIV and 1-752. pi. 1-2. f. 1-159. 1901; 2: 1-XII and 1-648. pi. 1-8. f. 1-181. 1903. , ("13). Gruppemveise Artbildung unter spezieller Berucksichtigung der Gattung Oenothera I-VII and 1-365. pi. 1-22. f. 1-121. 1913. Vuillemin, P. ('12). Les champignons. Essai de classification. 1-425. Paris, 1912. Welsford, E. J. ('07). Fertilization in Ascobolus furfuraceus. New Phytol. 6 156-161. pi. \. 1907. Werth, E., and Ludwigs, K. ('12). Zur Sporenbildung bei Rost- und Brandpilzen Ber. d. deut. bot. Ges. 30: 522-528. pi. 15. 1912. [Vol. 2, 1915] 376 ANNALS OF THE MISSOURI BOTANICAL GARDEN Wolf, F. A. ('12). The perfect stage of Actinonema Rosae. Bot. Gaz. 54- 218-234. pi. 13. 1912. Wolfe, J. J. ('04). Cytological studies on Nemalion. Ann. Bot. 18-607-630. pi 40-41. f. 51. 1904. Woronin, M. ('66). Zur Entwickelungsgeschi elite des Ascobolus pulcherrimus Cr. und einiger Pezizen. In deBary und Woronin, Beitr. z. Morph. u. Physiol, d, Pilze 2:1-11. pi. 1-4- 1866. y ('70). Sphaeria Lemaneae, Sordaria coprophila, fimiseda, Arthrobotrys oligospora. Ibid. 3: 1-36. pi 1-6. 1870. Woycicki, Z. ('04). Einige neue Beitriige zur Entwicklungsgeschichte von Basi- diobolus ranarum. Flora 93: 87-97. pi. 4. f. 1. 1904. Yamanouchi, S. ('06). The life history of Polysiphonia. Bot. Gaz. 42-401-449. pi. 19-28. 1906. Zukal, H. ('89). Entwicklungsgeschichtliche Untersuchungen aus dem Gebiete der Ascomyceten. K. Akad. Wiss., Wien, Math.- naturw. KL, Sitzun^sber. 98- 520-603. pi 1-4. 1889. A CONSPECTUS OF BACTERIAL DISEASES OF PLANTS ERWIN F. SMITH U. S. Department of Agriculture, Washington, D. C 1 All our knowledge of these diseases has come within a gen- eration. It began thirty-six years ago with the announcement of the bacterial origin of pear blight by Professor T. J. Bur- rill of the University of Illinois, who is with us to-day. During the first half of that period progress was slow and doubt uni- versal, especially in Europe. It is now eighteen years since I ventured the statement, that " there are in all probability as many bacterial diseases of plants as of animals. ' ' This statement was received with much skepticism, not to mention active opposition, but time has more than borne out my statement, and there is now no one left to dispute it. To-day I will venture another, and broader generalization, to wit : It appears likely that event- ually a bacterial disease will be found in every family of plants, from lowest to highest. This prediction is based on the fact that although the field is still a very new one, with no workers in most parts of the world, such diseases have been reported from every continent, and are already known to occur in plants of one hundred and forty genera distributed through more than fifty families. DISTRIBUTION Following Engler's arrangement, I will list these families that you may how wide is the distribution of bacterial diseases in plants and how utterly wrong were those who said that there were no such diseases, and also those who conceded a little but said that they were very rare and restricted to the soft underground parts of a few bulbous and tuberous plants, and generally preceded by fungi. In this list, I have included ly the flowering plants, but some of the cryptogams 1 Am. Nat. 30: p. 627. 1896. Ann. Mo. Bot. Gard., Vol. 2, 1915 (377) [Vol. 2 378 ANNALS OF THE MISSOURI BOTANICAL GARDEN subject to bacterial attack. The number following the family name indicates the number of bacterial diseases known within the limits of the family. The total of the figures, however, will not give the number of bacterial parasites, because some of the diseases overlap. TABLE I SHOWING THE FAMILIES OF FLOWERING PLANTS ARRANGED SERIALLY FROM LOWE* TO HIGHEST. THOSE CONTAINING GENERA SUBJECT TO BACTERIAL DISEASES ARE UNDERSCORED, AND WHEN SEVERAL DISEASES HAVE BEEN RECOGNIZED THEIR NUMBER IS ALSO GIVEN 1. Cycadaceae 2. Ginkgoaceae 3. Taxaceae 4. Pinaceae 2 5. Gnetaceae 6. Typhaceae 7. Pandanaceae 8. Sparganiaceae 9. Potamogetonaceae 10. Naiadaceae 11. Aponogetonaceae 12. Scheuchzeriaceae 12. Juncac/inaceae 13. Alismaceae 14. Butomaccae 15. Vallisneriaceae 15. Hydrocharitaceae 16. Triuridaceae 17. Poaceae 17 (traniineac 7 18. Cyperaeeae 19. Phoemcaceae 1!). Palmae 20 Cyclanthaceae 21. Araceae 22. Lonmaceae 23. Flagellariaceae 24. Baloskionaceae 24. Kestionaceae 25. Ontrolepidaceae 26. Mayacaceae 27. Xyridaceae 28. Erioeaulaceae 29. Ilapateaceae 30. Bromeliaceae 31. Commelinaceae 32. Pontederiaceae 33. Pliilydraceae 62. Liliaccac 34. Juncaceae 35. Stomonaceae 36. Melanthiaceae 37. Liliaceae 3 38. Convallariaceae 39. Smilacaceae 36. 37. 38. 39. 40. Haemodoraceae 41. Amaryllidaceae 42. Velloziaceae 43. Taccaceae 44. Diofleoreaceae 45. [ridaceae 46. Musaceaa 47. Zingiberaceae 48. Cannacrar 49. Marantaccac 50. Burmanniaceae 51. Orchidaceae 52. Casuarinaceae 53. Baururaceae 54. Piperaceac 55. Chloranthaceae 56. Salicaceae 2 57. JVlyricacea© 58. Balanopsidarcac 59. Leitneriaccae 60. Juglandaceac 2 61. BetulacM'ju' Fagaceae 63. Ulmaceae 64. Moraceae 65. Urticaceae 4 66. Proteaceae 67. Loranthaeeae 68. Myzodendraceae ('»!). Santalaceae 70. Grubbiaceae 71. Opiliaceae 72. Olacaceae 73. Balanophoraceae 74. Aristolochiacoae 75. Rafflesiaccae 76. Hydnoraceae 77. Polygonaceae 2 78. Chenopodiaoeae 4 79. Amaranthaceae 80. Nyctaginaceae 81. Batidaceae 82. Theligonacear 82. Cyno cram b aceae 83. Phvtolaccacei * 84. Aizoaceae 85. Portulacaoeae 86. Basellaceae 87. Silenaceae 87. Caryophyllaoeae 2 88. Nymphaeaceae 89. Ceratophyllaodeiiiaceae 295. Candolleaceae 296. Calyceraceae 297. Cichoriaceae 298. Ambrosiaceae 299. Asteraceae 297. 298. 299. Compositae 3 The widest gap, it will be observed, is between Cruciferae and Rosaceae, but I believe this represents nothing more than lack of knowledge. Also I should like to list the genera within the limits of which one or more species are now said to be subject to attack, because many of these genera contain plants of great economic importance. Where I have some personal knowledge of the subject I have italicized the genus name, and in what follows the reader will naturally expect me to draw illustrations prin- cipally from the diseases most familiar to me. TABLE IT SHOWING GENERA OF FLOWERING PLANTS SUBJECT TO DISEASES OF BACTERIAL ORIGIN Macrozamia Pi n u 5 Dactylis Bromus Zea Andropogon Avena Kacchamm Triticum Phleum Poa Cocos 1915] 381 D1VJLA X J Oreodoxa LI Ul\\y ± Vj±X±2\.±J A Beta Prosopis ( ?) Syr in ga Richardia Amaranthus Erythrina ' Olea Amorphophallus Dianthus Geranium Fraxinus Hyacinthus Delphinium Pelargonium Strychnos Allium Papaver Tropaeolum NerUwn Lilium Brassica Citrus Tectona Iris Raphanus Cedrela Verbena Ixia Cheiranthus Man i hot Capsicum Gladiolus Matthiola Mangifcra Solanum Musa Amelanchier Euonymus Lycopersicum Zingiber Sorbus Vitis Nicotiana Dendrobium Eryobotrya Gossypium Physalis Cattleya Pyrus Malva Petunia Oncidium Cydonia Sterculia Datura Odontoglossum Prunus Elodea Calceolaria Cypripedium Rub ns Begonia Sesamum Phalaenopsis Crataegus Opuntia Pavetta Vanilla Fragaria Eucalyptus Psycotria Salix Rosa Oenothera Benincasa Populus Heteromeles Aralia Cucumis Juglans Dolichos Hedcra Cucurbita Castanea Lathyrus Car ota Citrullus Corylus Indigofera Pastinaea Sicyos Morus Kraunhia ( ? ) Levistieum Echinocystis Pouzolzia Lupinus Apium Ageratum Cannabis Mucuna Arbutus Chrysanthemum Acalypha Phaseolus V accinium [ Lactuca Humulus Vigna Ardisia Blumea Ficus Pisum Crispardisia Synedrella Rheum- Trifolium Amblyanthus Tragopogon Polygonum Med lea go Amblyanthops: is Bellis Atriplex Arachis Diospyros 1 Aster Spinacia Acacia Ligustrum i PERIOD OF GREATEST SUSCEPTIBILITY In certain diseases the brief seedling stage of the plant is the one most subject to attack, e. g., Stewart's disease of maize due to Bacterium Stewarti, and brown rot of tomato and to- bacco due to Bacterium Solanacearum, but many bacterial diseases of older plants are also rather strictly time-limited. In both groups it is a question of abundant immature tissue. To the latter class belong the numerous leaf-spots, fruit-spots, and blights, e. g., black spot on the plum and peach, due to Bacterium Pruni, and fire-blight of the pear, apple, quince, etc., due to Bacillus amylovorus. In such cases, so far at least as they occur in temperate climates, the disease appears in \ [Vol. 2 382 ANNALS OF THE MISSOURI BOTANICAL GARDEN the spring and the greater part of it occurs during a brief period in the early summer, in which growth of roots, leaves and shoots is proceeding rapidly and there are many young and succulent parts. The cause of the disease may and often does remain on the plant over winter in a latent or semi-latent condition (walnut blight, pear blight, plum canker), but the active period is limited to three months, more or less, of actively growing weather in which developing tissues, subject to infection, are abundant. With definitive growth and the hardening of the tissues in late summer and autumn, the disease is checked and disappears, or remains as a slow canker to appear again on other parts the following spring. It is a very instructive experiment to see, for example, inoculations of Bacillus amylovorus on ripening fruits and shoots of the pear wholly fail toward the end of July, which were eminently successful on the same trees at the beginning of June. The b .. lllli , b difference in this case is not due to lessened virulence on the part of the organism, but to changes in the host-plant, making it non-susceptible. Similar changes leading to non-suscepti- bility occur in the Japanese plum subject to Bacterium Pruni; the young fruits are very susceptible, the maturing fruits cannot be infected. Other parasites on the contrary are able to attack, disin- tegrate and destroy matured tissues, e. g., the pith of cabbage stems, turnip roots, the ripened tubers of the potato, well de- veloped roots of sugar beets, the bulbs of onions and hyacinths, full-grown melon and cucumber fruits. In both of these types the action of the parasite is expended chiefly on the parenchyma, although in some cases (the plum disease, AppePs potato rot) there is more or less bacterial invasion of the local vessels. Vascular occupation is not a special characteristic. In the typical vascular diseases the case is reversed. Here parenchyma is also destroyed, more or loss, but the most con- spicuous and destructive action is on the vascular bundles themselves, which are occupied for long distances, to the death, or great detriment, of the whole plant. In maize attacked by Bacterium Stewarti, it is not unusual, indeed one might rather 1915] SMITH BACTERIAL DISEASES OF PLANTS 383 say it is customary, to find the vessels of the stem filled with the bacteria continuously for a distance of 3-6 feet from the point of infection, i. e., from the surface of the earth to the top of the full-grown plant. In cucurbits attacked by Bacillus tracheiphilus and in sugar-cane attacked by Bacterium vas- cularum the same thing occurs, and many of the vessels are filled solid with the bacterial slime to a distance of 8 or 10 feet from the place of infection. In such cases infection has taken place generally near the base of the plant, which continues to grow for some weeks or months. Transitions, of course, occur. Bacterium Stewarti, for ex- ample, is confined much more strictly to the vascular bundles of the maize stem than is Bacterium Solanacearum to those of the tomato, potato, or tobacco stem, although it also is a vascular parasite; that is, following infection of the vessels not find in the maize stems that extensive breaking we do not down of the pith and phloem into vast cavities which common, for examine, in tobacco and tomato stems. so WHAT GOVERNS INFECTION Within the plant we may suppose, from certain indications, that abundant juiciness is the chief factor governing the in- fection of immature tissues. To this may be added an abun- dant well-adapted food supply and, in some cases, probably I the absence of inhibiting substances, which may appear later. As the parts approach maturity the water content becomes less. Along with this, acids, sugars, amids, proteids, etc., are consumed and converted into substances less well adapted to the needs of the meristem-parasites, if not wholly inimical. In young shoots of potato and tomato, or of pear and apple, as contrasted with old ones, or in the roots of carrots as com- pared with the leaves, or in rapidly-growing cabbages, as compared with slow-growing ones, we know that there is an excess of water, and this alone appears to be sufficient to ex- plain the difference in behavior of their respective parasites in old versus young parts. When, however, we come to ripen- ing fruits, such as the pear and the plum, it would seem that they are still juicy enough to favor the growth of almost any [Vol. 2 384 ANNALS OF THE MISSOURI BOTANICAL GARDEN bacterium, and we are forced to the hypothesis of chemical changes within the fruits to account for the failure of inocula- tions. As a rule (there are striking exceptions), parasitic micro-organisms are rather sensitive to changes in their en- vironment, e. g., to drying, exhaustion of food supplies, multi- plication of their own by-products, conversion of an easily assimilable substance into one less assimilable or actually harmful, appearance of esters, new acids, etc. But why speculate! Much additional experimenting must be under- taken before we shall have precise and full data. We are still largely in the observational stage. The parasites of ripened tissues do not require so much water, are able to convert starch into sugar, or have a special liking for some other element of the plant tissue. Externally, a number of factors favor infection. One of these is excessive shade, either of clouds or of foliage. An- other is high temperature. When these two factors arc; ac- companied by excessive rainfall, wet earth, and heavy dews, the conditions are ideal for the rapid dissemination and the destructive prevalence of a variety of bacterial diseases of cultivated plants. The bean spot due to Bacterium Phaseoli, the black spot of plum due to Bacterium Pruni, and the lark- spur disease due to Bacterium Delpliinii, are all favored by heavy dews and by shade. In hot, wet weather in duly pear blight due to Bacillus amylovorus often bursts out like a con- flagration and sweeps over whole orchards. In warm, moist autumns bacterial diseases of the potato may destroy almost or quite the entire crop over extensive districts. HOW INFECTION OCCURS As I have already described elsewhere how infection oc- curs, 1 I will only dwell for a moment on it here, offering a few examples. The commonest way of infection is probably through wounds. 1 Smith, E. F. Bacteria in relation to plant diseases. Carnegie Inst. Wash- ington, Publ. 27* : pp. 51-C4. 1911. 1915] SMITH BACTERIAL DISEASES OF PLANTS 385 In Italy, the olive tubercle due to Bacterium Savastanoi has been observed to begin very often in wounds made by hail- stones. In South Africa, crown-gall is said to be disseminated in the same way. In this country and also in Sumatra, Bac- terium Solanacearum enters the plant more often than other- wise through broken roots. A tomato or tobacco plant with unbroken roots will thrive in a soil deadly to one that has been root-pruned. I have myself observed this. We may suppose that substances attractive to the particular bacteria diffuse into the soil from the broken roots, following which they enter the plant. Eesistant plants may be supposed to diffuse indifferent or repellant substances. All infections must be chemotactic. More interesting perhaps are those diseases which begin in natural openings, i. e., in places where the protective covering of the plant gives place to special organs such as nectaries, water-pores, and stomata. All the pome fruits subject to fire-blight are liable to blos- som infection. The bacteria multiply first in the nectaries of the flower, passing down into the stem by way of the ovary and pedicel. Blossom blight of the pear is a very conspicuous and common form of the disease as everybody knows. Thou- sands of blighted blossom clusters may be seen in any large orchard subject to this disease. In the black rot of the cabbage due to Bacterium campestre, the majority of the infections begin in the water-pores. These are grouped on the margins of the leaf at the tips of the ser- ratures. From this point the bacteria burrow into the vas- cular system of the leaf and so pass downward into the stem and upward into other leaves. In the black spot of the plum, almost or quite all of the infections are stomatal. A large proportion of them are also stomatal in the leaf-spot of cotton, and other leaf-spots. TIME BETWEEN INFECTION AND APPEARANCE OF THE DISEASE As in animal diseases, the period of latency may be very short or surprisingly long. Some time must be allowed the parasitic organism to multiply inside the plant before it does [Vol 1 386 ANNALS OF THE MISSOURI BOTANICAL GARDEN damage serious enough to be recognized externally as a dis- ease. This is the so-called "period of incubation," during which the parasite is growing and its enzymes and toxins are becoming active. The microscope shows it to be present in the tissues, but the latter have yielded only a little in the immediate vicinity of the bacterial focus. This time is short or long depending on whether the parasite or the host has the first advantage. If the host is growing rapidly it may either en- tirely outstrip the parasite, or be only so much the more sub- ject to it. All depends on whether the parasite finds the initial conditions entirely suited to its needs, or by means of its secretions and excretions can quickly make them so, and con- sequently can from the start make a rapid growth, or must first slowly overcome obstacles of various sorts, such as in- hibiting acids and resistant tissues. The plant may show signs of infection within as short a time as one or two days after inoculation (various soft rots), or it may be as long a time as one to two months before they appear (Cobb's disease of sugar-cane, Stewart's disease of sweet-corn). In the latter, infection generally occurs in the seedling stage and the maize plant may be three months old and six feet tall before it finally succumbs. Of course, as in case of bacterial animal diseases, the greater the volume of infectious material the shorter the time. I have seen many instances of that law. In general, the period of latency may be said to vary from one to three w r eeks (yellow disease of hyacinth, black rot of cabbage, black spot of plum, cucurbit wilt, pear blight, angular leaf-spot of cotton, sorghum leaf -stripe, etc.). RECOVERY FROM DISEASE Mention has already been made of the self -limited spot diseases and blights. As the actively growing season draws to a close such diseases cease their activity. Also in some plants well developed signs of vascular dis- ease may be suppressed (squash, maize, sugar-cane) or re- main in abeyance for a longer or shorter period, according to the varying fortunes of the host and the capabilities of the parasite. The tomato plants inoculated with Bacterium Sol- 1915J SMITH BACTERIAL DISEASES OF PLANTS 387 anacearum (Medan hi) and photographed for Volume in of 'Bacteria in Eelation to Plant Diseases' (plate 45 D), en- tirely outgrew the disease, as did also certain sugar-canes (series vi) inoculated with Bacterium vascularum. 1 Also, I have seen tomato plants recover only to develop a second and fatal attack of the vascular brown rot three months after the first attack, during which period they had made an extensive healthy-looking growth. 2 Recovery from disease may depend on loss virulence on the part of the parasite. This often occurs when bacteria are grown for some time on culture-media, and it occurs also in nature, but its cause is obscure. AGENTS OF TRANSMISSION These may be organic or inorganic. In many cases the plant itself harbors the parasite indefinitely, carrying it over from year to year on some portion of its growth. Seeds, tubers, bulbs, grafts, or the whole plant may be re- sponsible for the appearance of the disease the following year in the old localities, and through the agency of seedsmen, nurserymen, or whoever disseminates plants, for outbreaks in regions hitherto exempt. There is good reason to believe that the black rot of cabbage and Stewart's disease of sweet corn have been disseminated broadcast in the United States in recent years by ignorant and unscrupulous seedsmen. Both diseases are transmitted to seedling plants from the seed. The yellow disease of hya- cinths is carried in the bulb. Potato tubers from diseased fields may infect healthy fields. Apple grafts have transmit- ted crown-gall. Slightly infected trunks and limbs of trees (hold-over pear blight, walnut blight, canker of the plum) may infect shoots, leaves, blossoms, or fruits the following season. The soil around the infected plant may serve for years as a source of infection to other species (crown-gall), or to other individuals of the same kind (various leaf-spots). Occasion- ally, however, a parasite seems to die out of certain soils {Bac- 1 Smith, E. F. Bacteria in relation to plant diseases. Carnegie Inst. Wash- ington, Publ. 27 s : p. 33. 1914. 2 Ibid. p. 179. [Vol. 2 388 ANNALS OF THE MISSOURI BOTANICAL GARDEN terium Solanacearum). The pear blight organism probably dies out of soils quickly as it does in a majority of the blighted branches. Pear blight by soil infection is not known. Among extraneous agents, wind and water have been sus- pected. I have never seen any clear indications of wind-borne infection, not even when conditions seemed to invite it, but water often carries parasites and furnishes conditions favor- able to infection. Home has shown that the olive tubercle in California is transmitted in this way. Honing, in the tobacco fields of Sumatra, has traced infection several times to the watering of plants from infected wells, and has cultivated the parasite from the water. I have discovered experi- mentally that to obtain several sorts of bacterial leaf-spots (bean, cotton, peach, plum, carnation, larkspur, sorghum, geranium) the surface of the leaves must be kept moist to the same extent they would be in case of prolonged dews or fre- quent light showers. Such conditions are necessary to enable the bacteria to penetrate the stomata and begin to grow. In case of water-pores, however, the plant itself furnishes the water necessary for infection, if the nights are cool enough, i. e., if the air remains near enough to saturation to prevent for some hours the evaporation of the excreted water from the leaf-serratures. Every plant with functioning water-pores awaits its appropriate bacterial parasite. The genus Im- patiens is a good example. I have looked on it for one in vain but I am sure it must occur. Man and the domestic animals, especially through the agency of the dung-heap, infallible repository of all sorts of discarded refuse, undoubtedly help to spread certain bacterial diseases of plants (potato rots, black rot of cabbage, etc.). Birds probably transmit some of these diseases on their feet or in other ways. In connection with the bud-rot of the coconut palm in the West Indies, I suspect the turkey-buzzard, but the evidence Mr. Waite ob tained (once in Florida, once in Maryland) the strongest kind of circumstantial evidence going to show that pear blight may be spread by birds. 1915] SMITH BACTERIAL DISEASES OF PLANTS 389 molluscs, and worms, the evidence is I have Respecting insects, mplete. They often serve to carry these diseases summarized our knowledge in another pi and will here by insects long before the animal content myself with a brief statement calling renewed atten- tion to the subject. We had very good evidence of the transmission of one bac terial disease of plants pathologists awoke to the importance of the subject, 2 but it cannot be said that they have ever paid much attention to it, although it antedates by two years the work by Theobald Smith and Kilborne showing that Texas fever is transmitted by the cattle tick (Ixodes bovis). That discovery also belongs to the credit of the U. S. Department of Agriculture, and the two together may be said to have laid broad and deep the foun- dations of this most important branch of modern pathology. Waite isolated the pear blight organism, grew it in pure cul- tures, and proved its infectious nature by inoculations. With such proved cultures he sprayed clusters of pear flowers in places where the disease did not occur and obtained blossom- blight, and later saw this give rise to the blight of the sup- porting branch, found the organism multiplying and reisolated it from the blighting blossoms On some tr he restricted the disease to the sprayed flowers by covering them with mosquito netting to keep away bees and other nectar-sipping insects. On other trees where the flowers were not covered he saw bees visit them, sip from the inoculated blossoms and afterwards visit blossoms on unsprayed parts of the tree which then blighted. Finally he captured bees that had visited such infected blossoms, excised their mouth parts, and from these, on agar-poured plates, obtained Bacillus amulovorus, with colonies of which he again produced the dis- These experiments were done in several widely sepa- rated localities with identical results. I saw them and they made a great impression on me 1 Smith, E. F. Bacteria in relation to plant diseases, ington, Publ. 27": p. 40. 1911. ease. Wash 2 Waite, M. B. Results from recent investigations in pear blight. Bot. Gaz. 40 1891. . 390 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 The writer has since proved several diseases to be trans- mitted by insects, notably the wilt of cucurbits, and here the transmission is not purely accidental, but there appears to be an adaptation, the striped beetle (Diabrotica vittata), chiefly responsible for the spread of the disease, being fonder of the diseased parts of the plant than of the healthy parts. This acquired taste, for it must be that, works great harm to melons, squashes, and cucumbers. Whether the organism winters over in the beetles, as I suspect, remains to be determined. Certainly the disease appears in bitten places on the leaves very soon after the spring advent of the beetles. In 1897 I showed that molluscs sometimes transmit brown rot of the cabbage, and last year I saw indications in Southern France which lead me to think that snails are responsible for the spread of the oleander tubercle, i. e., I saw them eating both sound and tubercular leaves, and found young tubercles developing in the eroded margins of bitten leaves. Parasitic nematodes break the root tissues and open the way for the entrance of Bacterium S olanacearum into tobacco and tomato, as was first observed by Hunger in Java and later by myself in the United States. One of the serious problems of plant pathology is how to control lleterodera radicicola, not only because of its wide distribution on a great variety of cultivated plants and the direct injury it works, but also on account of the often very much greater injury it causes through the introduction into the roots of the plant of bacterial and fungous parasites. The man who shall discover an effect- ive remedy will deserve a monument more enduring than brass. Our Southern States in particular are overrun with this parasite. Much remains to be done before we shall know to what ex- tent fungous parasites function as carriers of parasitic bac- teria. H. Marshall Ward sought to explain the presence of bacteria in diseased plants by supposing that they must enter the plant through the lumen of fungous hyphae. In this lie was wrong, certainly if it be stated as a general proposi- tion, but it appears to be clear that in some cases the two types of parasites work together, the fungus invading first, and the . 1915] SMITH BACTERIAL DISEASES OP PLANTS 391 bacterium following hard after and often doing the major part of the damage. The reverse of this also occurs, the bacterium entering first and the fungus following. ! Parasitic bacteria are soon followed by saprophytic bacteria which complete the destruction of the tissues, and, if the dis- ease is somewhat advanced, cultures from the tissues may yield only the (potato rots). Also, as in animals parasitic disease may follow another and the second be more destructive than the first, e. g., fire-blight following crown-trail on the apple. EXTRA-VEGETAL HABITAT OF THE PARASITES Here is perhaps the place to say a few words about the non- parasitic life of the attacking organisms. All are able to grow saprophytically, i. e., on culture media of one sort or another, and probably all live or may live for soil. Very few, however, have been cultivated time in the from The vast mixture of organisms present in a good earth rather discoura 6 In some of the unsuccessful attempts failure may have been due to not having undertaken at exactly the right time, or in just the right the proper medium, but more often probably swamping tendency of rapidly growing saprophytes, long a parasite is able to maintain its virulent life in a must depend largely on the kind of competitors it finds, have used the term virulent, because it is conceivable that organism might remain alive in a soil long after losing How I infect plants, just as we know it can in culture media ium Solana o brown rot of Solanaceae Bacillus phytophthorus causing basal stem rot and tuber of the potato, and Bacterium tumefaciens causing crown-; such soils, especially disease, if thev belon )il, and the soundest plants when set in if wounded, are liable to contract the to susceptible species. The root-nodule organism of Leguminosae, which I have not considered here also lives in many soils, as every one knows. [Vol. 2 392 ANNALS OF THE MISSOURI L50TANICAL GARDEN MORPHOLOGY AND CULTURAL CHARACTERS OF THE PARASITES Most of the plant bacteria are small or medium sized rod- shaped organisms. Very few parasitic coccus forms are known. In fact, none are very well established. Some of these bacteria are Gram positive, others are not. All take stains, especially the basic anilin dyes, but not all stain with the same dye or equally well. Most of the species are motile by means of flagella — polar or peritrichiate. A few are non- motile, genus Aplanobacter. 1 Some develop conspicuous cap- sules, others do not. Few, if any, produce endospores. Grown pure on culture media in mass, they are either yellow, pure white, or brownish or greenish from the liberation of pigments. Red or purple parasites are not known. We for- merly supposed that there were no green fluorescent species capable of parasitism, but now several are known, e. g., the organism causing the lilac blight of Holland, with pure cul- tures of which the writer obtained typical infections at Amsterdam in 1906, and afterwards in the United States (now first recorded). Some species produce gas, liquefy gelatin, consume asparagin, destroy starch, and reduce ni- trates ; others do not. Their fondness for sugars and alcohols is quite variable. Some are extremely sensitive to sunlight and dry air (Bacillus carotovorus, Bacillus tracheiphilus). Others are remarkably resistant, remaining alive and infec- tious on dry seeds for a year (Bacterium campestre, Bac- terium Stewarti, Aplanobacter Rathayi). Some are strictly aerobic, others can grow in the absence of air, if proper foods are available. Some are very sensitive to acids, alkalies and sodium chlorid, others are not. Some have wide ranges of growth from 0°C. upwards. Some will not grow at or near 0°C, others will grow at or above 40° C. Very few, however, will grow at blood temperature, certain ones even in plants or on culture media are killed by summer temperatures, and none are known definitely to be animal parasites. 1 Smith, E. F. Bacteria in relation to plant diseases. Carnegie Inst. Wash- ington. Publ. 27 1 : p. 171. 1905; Ibid. 27 8 : pp. 155, 161. 1914. 1915] SMITH — -BACTERIAL DISEASES OF PLANTS 393 ACTION OF THE PARASITE ON THE PLANT In some cases it is hard to draw the line between parasitism and symbiosis or mutualism. Probably we shall find more and more of these transition states. I have included Ardisia in my list of genera and have excluded the genera of legumes subject only to root nodules. But a nodule on the root of a legume, so far as the local condition is concerned, is a disease as much as a leaf-spot, and, if Nobbe and Hiltner's statements are to be credited, the general effect of the root-nodule or- ganism on the plant may be excessive and injurious and not to be distinguished from a disease. 1 In the tropical East Indian Ardisia, which of the strangest cases of mutualism known to me, and on which Miehe has done such a beautiful piece of work, we perhap have mething akin to what the root nodules of legumes He the bacterial injury is local and internal There are no superficial indications of dise The bacte most abundant in the leaf-teeth where they form pockets savities and multiply enough to make the leaf serratures ear blanched or yellowish and slightly swollen, but never gh to kill them In smaller numbers the bacteria in other parts of the plant including the inner parts of the seed from which they are transmitted to the seedling, whose leaf serratures, infected through their water-pores, in become the chief focus of the bacterial multiplication Ap parently the bacteria are always present, and we do not what would happ Ardisia plants without them, nor do we know how to obtain such plants. It would be an interesting experiment to see if they could be produced and to watch their behavior. The action of such organisms as I have mentioned differs probably from the behavior of active parasites in that they liberate much weaker toxins and enzymes, can attack only very actively growing parts, and also give off compensating nitrog- enous substances. Not yet proved for Ardisia. 1 Smith, E. F. Bacteria in relation to plant diseases. Carnegie Inst. Wash- ington, Publ. 27 2 : p. 131, last paragraph. 1911. 394 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 The active parasites produce toxins freely, poisoning the tissues, and enzymes converting starches into sugars, com- plex sugars into simpler ones, and so on, for their nutrition. They also neutralize and consume plant acids, and feed upon amido bodies and other nitrogenous elements of the host. As a result of their growth, many of them liberate both acids and alkalis to the detriment of the plant. The solvent action of their products on the middle lamellae separates cells and leads to the production of cavities in the bark, \nth, phloem and xylem. There is also, or may be, a mechanical splitting, tear- ing or crushing due to the enormous multiplication of the bac- teria within confined spaces. The whole intercellular mech- anism may be honeycombed and flooded in this way, and if the cavities are near the surface the tissues may be lifted up or the bacteria may be forced to the surface through stomata in the form of tiny beads or threads (pear, plum, bean, maize, sugar-cane, etc.), or by a splitting process. The split ling in the black spot of plum fruits and peach fruits, however, results from local death of the attacked tissue with continued growth of the surrounding uninjured parts. A majority of the forms known to cause plant diseases are extra-cellular parasites occupying chiefly the vessels and inter- cellular spaces, causing vascular diseases, soft rots, spot dis- eases, etc. But intra-cellular parasites also occur, e. g., Bac- terium Leguminosarum causing root-nodules on legumes, and Bacterium tumefaciens causing crown-gall. The former mul- tiplies within the cell myriadfold, prevents its division, destroys its contents including the nucleus, and enormously stretches the cell wall so that the cell becomes much larger than its normal fellow cells and is packed full of the bacteria. The latter does not multiply abundantly within the cell, does not enlarge it, does not injure its viability, and would be a harmless messmate were it not for the fact that it exerts a stimulating effect on the cell nucleus, compelling the cell to divide again and again. THE REACTION OF TIIK PLANT We now come to the reaction of the plant. What response does it make to this rude invasion? Ten years ago we might 1915] SMITH BACTERIAL DISEASES OF PLANTS 395 have said, "With rare exceptions, the plant is passive or nearly so," but that would have been a superficial obser In disease must suppose that the makes some effort to throw off the intruder, although often its forces are paralyzed and overcome very early in the progress of the disease. One of the most conspicuous results is lessened growth. In some of my plants recovering from brown rot due to Bac- Solan month aft signs of the disease had disappeared the check plants were twice the size of the inoculated ones, and there was still a very decided dif- ference after more than two months. I do not know how to explain this checked growth unless it be the response to ab- sorbed toxins. On potato plants attacked early by Bacterium Solanacearum small. On maize attacked by Bacterium the tubers remain small. Stewarti the ears are imperfect Olive shoots inoculated and infected by Bacterium S avast anoi are always dwarfed, and gall dwarfin frequently The dwarfing of melon and squash plants attacked by Bacillus tracheiphilus is also conspicuous. Uninoculated sugar-cane stems soon surpass in height and vigor those successfully in- oculated with Bacterium vascularum. Changes in color The attacked parts iy become greener than normal, or fade to yellow, red, brown black. In tomato fruits there is often a retarded ripening persistence of the chlorophyll. In certain leaf on the attacked side with persi Crown-galls on daisy are greenish the leaf green persists in the vicinity of the spot rest of the leaf becomes yellow yellow (bean-leaf spot of maize attacked by Bacterium St The male prematurely and becomes white Distortions of various kinds of bean, lilac The leaves oi larkspur, hyacinth, mulberry, Persian walnut) . The tomato plants attacked by Bacterium Solanacearum are bent downwards: so are the fronds of the coconut palm when 1 Smith, E. F. Bacteria in relation to plant diseases. Carnegie Inst. Wash- ington : Publ. 27 s : pi. 45-D. 1914. 396 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 attacked by the bacterial bud-rot. Knee-shaped curvatures of the culms appear on Dactylis attacked by Aplanobacter Rathayi, and in the buds of the sugar-cane attacked by Cobb's disease. Organs may be developed in excessive number or out of place, as roots in hairy-root of the apple, witch-brooms on Pinus, and incipient roots on the stems of tomato, tobacco, chrysanthemum, nasturtium, etc. Hunger found a bud on a tomato leaflet which he attributed to the stimulus of Bac- terium Solanacearum. In various diseases the plant removes starch from the vicin- ity of the bacterial focus which it endeavors to wall off by the formation of a cork barrier, and in this effort it is sometimes successful if the parasite is growing slowly. The most conspicuous response of the plant is in the form of pathological overgrowths, — cankers, tubercles, and tumors. Some of these are very striking, e. g., those on the ash, olive, pine, oleander, and on a multitude of plants attacked by crown- gall. In some of these growths there is a great reduction of the vascular system, and a great multiplication and simplifica- tion of the parenchyma. There are also various other phe- nomena nearly related to what takes place in certain insect galls. In crown gall cell division under compulsion proceeds at such an abnormally rapid rate that the cells are forced to divide while still immature, and in this way masses of small- celled unripe (anaplastic) tissue arise. These develop tumor- strands on which secondary tumors arise. PREVALENCE AND GEOGRAPHICAL DISTRIBUTION Economically considered, bacterial diseases of plants may be classed as major or minor. Most of the leaf-spots would fall into the latter class. Various soft rots, blights and vascular diseases, being wide-spread and destructive to plants of great economic importance, may be classed as major diseases. Cankers and tumors would fall midway in such a grouping. Occasionally a minor disease, e. g., lettuce rot, celery rot, under favorable conditions may assume great importance. 1915] SMITH BACTERIAL DISEASES OF PLANTS 397 It will be of interest to mention a few of these diseases with particular reference to their distribution and prevalence. Dutch East Indies.— The tobacco disease of Sumatra and Java is probably the most destructive, if the Sereh of cane is not bacterial. Each of these diseas enormous losses. Each threatens an industry has caused The tobacco disease occurs also in the West Indies, in the United States and probably also in South Afi If Janse's root disease of Erythrina, the coffee shade tree of Java, is also bacterial, as he supposed, then there is another great bacterial plague in that region, for hundreds of thousands of trees have died, and another species has been substituted as a shade tree. West Indies.— Here the most destructive disease is the bac- terial bud-rot of the coconut palm, which occurs all around the Caribbean, and threatens the entire destruction of a profitable in Cuba. There is also the bacterial disease of industry bananas and plantains, but the structive Musa di * Panama disease, due to a Fusarium mo wide-spread and de of the Western Hemisphere is the A Cobb's disease of sugar-cane has probably tracted more attention in Australia than any other bacterial trouble, although bacterial rots of the potato are also very destructive. The cane disease in both Queensland and New South Wales has in many cases destroyed the output of whole plantations and greatly discouraged planters. This disease occurs also in Fiji, and probably in South America. Probably the tobacco wilt, which has destroyed Ja many fields, is the worst Japa d be identical with the tobacco wilt of Sumatra and of the United States. Several other bacterial blights h been ted. including one of the basket willow In brown rot of Sol common and de structive. Most of Asia South Af The mango disease in recent years has greatly reduced the exports. Potato and tomato wilts are There is a serious tobacco disease, probably bac- a-gall is common and injurious on shade and common terial. Crow orchard trees Other diseases 398 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. -l South America. — There is a serious disease of sugar-cane in Brazil and another in Argentina, both of which I believe are of bacterial origin, and identical with Cobb's disease. Bondar has reported a destructive manihot disease. The bud-rot of the coconut occurs in the north. United States and Canada. — Potato rots probably cause the greatest losses one year with another. Following these I should think pear and apple blight. Perhaps the latter should be placed first, for the destruction of an acre of potatoes would scarcely equal the value of a single fine pear tree, and thou- sands are destroyed every year. In California, which was free from pear blight until recently, the losses in the last fif- teen years have been enormous, amounting to about one-third of all the full-grown orchards and to a money-loss estimated at $10,000,000 for the five years preceding the efforts for its restriction begun in 1905 by the U. S. Department of Agri- culture. Very serious losses from this disease are experi- enced every year in the East, or were until growers became generally familiar with methods of control. In our southern states the tobacco and the tomato wilt have made it impossible to grow these crops on many fields. In the northern United States the cucurbit wilt is wide-spread and destructive, but cucurbits are of course a minor crop. The walnut blight has done much damage in California. This occurs also in New Zealand and Tasmania. The bacterial disease of alfalfa has been serious in parts of the West. It is most injurious early in the season, i. e., on the first cutting. Holland. — Here the yellow disease of hyacinths is always destructive and will eventually put an end to hyacinth-growing for export if means cannot be had for its control, since the land suited for hyacinths is limited in amount. Brown rot of cab- bage occurs in Holland and Denmark, and is common now also in many parts of the United States. It was probably imported into the United States from Denmark on cabbage seed. Some years in nurseries about Amsterdam the lilac blight has been troublesome. 1915] SMITH BACTERIAL DISEASES OF PLANTS 399 Great Britain and Germ Potato rots are probably the most destructive bacterial diseases. j France and Italy. — Potato diseases are common, tubercle, common also in California, and all around the Medi Olive terrar is prevalent in spots Vine dise lly Maladie d'Oleran and crown-gall, do considerable damage. Pear blight seems to be absent in France, but has been re- ported from several places in Italy. The destructive Italian rice disease, brusone, is not due to bacteria as reported, but to a fungus {Piricularia) . METHODS OF CONTROL In conclusion, some words on prophylaxis will be in order. Until recently almost nothing was known. Unfortunately so far as regards most of these diseases, methods of control must still be worked out. But with rapidly increasing knowledge of the biological peculiarities of the parasites causing these diseases, and of the ways in which they are disseminated, light begins to dawn, so that before many years have passed we may confidently expect the more intelligent part of the public to be applying sound rules for the control of these diseases rules based on the individual peculiarities of the parasites and carefully worked out experimentally by the plant pathologist. The little that we now know may be summarized in part as follows : Waite has shown that pear blight winters over in excep- tional trees on trunk and limbs in the form of patches which ooze living bacteria the following spring and are visited by bees and other insects, and that if these "hold spots are cut out thoroughly over regions several miles in diameter (wide as a bee flies), the disease does not appear on the blos- soms and shoots the following spring, except as it is intro- duced into the margins of this area from remoter uncontrolled districts. He has tried this method of control very success- fully, both in Georgia and California. Sometimes only one tree in many carries over the disease, but such is not always the case, and the success of this method involves the inspec- tion of every pome tree in a district with complete eradication I Vol. 2 400 ANNALS OF THE MISSOURI BOTANICAL GARDEN of every case of the hold-over blight, and this in great fruit regions requires a small army of trained inspectors. During the blighting period in late spring and early summer, if one would save his orchard, the trees must be cut over for removal of diseased material as often as every week, and in the worst weather oftener. The introduction of diseases transmitted by way of seeds, bulbs, and tubers may be avoided by obtaining these from plants not subject to the disease. As this freedom cannot always be known, bulbs and tubers should be inspected criti- cally before planting, and firm-coated seeds should be soaked for 15 minutes in 1 :1000 mercuric chlorid water. In case of two plants (cabbage and maize) we know positively that the diseases are transmitted on the seed and this is probably true for several others — beans, sorghum, orchard grass. All shrivelled seeds should be screened out before planting. The seed bed in case of tobacco, tomato, cabbage, and trans- planted plants generally, should be made on steam-heated or fire-heated soil, or new earth which one has good reason to think free from the parasite in question. Nematode-infected soil should be avoided. Cuttings of carnations, chrysanthemums, roses, peaches, plums, apples, quinces, sugar-cane, etc., used for slips, buds, or grafts should be from sound plants. By following this practice, recommended in case of sugar-cane by Cobb, the more intelligent cane planters in New South Wales have overcome the disease due to Bacterium vascularum. On badly infested soils a careful long rotation should be practised and the low places should be drained. Certain diseases may be held in check by germicidal sprays. Pierce reduced the number of infections in walnut blight fifty per cent by this method. Scott and Rorer combated leaf- spot of the peach in this way, the sprayed trees retaining their leaves, the unsprayed ones becoming defoliated. in Italy has recommended it and used it successfully on olive trees following hail-storms to keep out the olive tubercle. When diseases are transmitted by insects the destruction of the latter must receive prompt attention. 1915] SMITH BACTERIAL DISEASES OP PLANTS 401 Great care should be taken to keep the manure heap free from infection. Diseased rubbish should be burned or buried deeply. It must not be thrown into a water supply or fed stock or dumped into the barnyard. It has been found that some varieties of plants are less sub iect to disease than others um, maize, potato tomato, susrar-cane, banana, cabbajre. etc.). and there individual These phenomena lead us to hope that by selection, or hybridization, valuable re- sistant strains may be originated. Meanwhile the resistant sorts when they are of any value commercially should be sub- tuted for sensitive sorts in localities much subject to the lease. Unfortunately some of the resistant sorts have other di desirable qualities. A vast amount of experimental work must be done in this field before we shall have substantial re- sults, and at least a generation or two will be required to learn even the boundaries of the field. But the problem offered is so enticing and has such immediately practical bearings that in the near future we may suppose many pathologists will de- vote themselves to it, and that long before the whole field is worked over, many useful results will be forthcoming. The labor involved is enormous and exacting to discouragement at times, the results come so slowly, so much must be done to be certain of so little, all because the organisms dealt with are very small — how small, we seldom realize! Many a time in the past when downcast I have repeated to myself Seneca's rolling words, Palma non sine pulvere per viam rectam, and have had more or less encouragement out of them. They are a good motto for any man, since nothing is more certain than this, that without plenty of well-directed hard work there can be no worthy success in any field of human endeavor. Volume II umbers 1 and 2 nnals of the Missouri Botanical Garden Anniversary Proceedings Contents February-April, 1915 The Twenty-fifth Anniversary Celebration 1-32 The Vegetation of Mona Island N. L. Britton 33- 58 The Flora of Norway and its Immigration. . N. Wille 59-108 The Phylogenetic Taxonomy of Flowering Plants C. E. Bessey 109-164 The Botanical Garden of Oaxaca C. Conzatti 165-174 The Origin of Monocotyledony J. M. Coulter 175-183 The History and Functions of Botanic Gardens '. . A. W. Hill 185-240 Recent Investigations on the Protoplasm of Plant Cells and its Colloidal Properties F. Czapek 241-252 The Experimental Modification of Germ-Plasm .. D. T. MacDougal 253-274 The Relations between Scientific Botany and Phytopathology O. Appel ... 275-285 The Law of Temperature Connected with the Distribution of the Marine Algae W A. Setchell 287-305 Phytopathology in the Tropics Johanna Westerdijk 307-313 Phj'logeny and Relationships in the Ascomycetes. . .G. F. Atkinson 315-376 A Conspectus of Bacterial Diseases of Plants E. F. Smith 377-401 PUBLISHED QUARTERLY BY THE BOARD OF TRUSTEES OF THE MISSOURI BOTANICAL GARDEN, ST. LOUIS, MISSOURI red a* gecond-rlflRH matter at tb* Post Office at I I on\% Misaonri, tinder the Art of March 3, 1875*. I nnals of the Missouri Botanical Garden A Quarterly Journal containing Scientific Contributio from the Missouri Botanical Garden and the Graduate I aboi tory of the Henry Shaw School of Botany of Washingfc University in affiliation with the Missouri Botanical Garde Editorial Committee G< rge T. Moore Jacob R. Schramm Benjamin M. Duggar Information The Annals of the Missouri Botanical Garden appears four times dur- ing the .calendar year, February, April, September, and November. Four numbers constitute a volume. Subscription Price urn- foreign Wesley & Son, 28 1 ex Street, Strand, London STAFF OF THE MISSOURI BOTANICAL GARDEN Director, GEORGE T. MOORE. Be MXH M. DUGGAB, Physiologist, In charge of Graduate Laboratory. Hermann von Schbenk, Plant Pathologist. JESSE M. GbEenman, C orator of the Herbarium. Edwabd A. Bubt, Mycologist anil Librarian. Jacob R. Suhbakm, Assistant to the Director. Chables H Thompson, Assistant Botanist. Melvin C. Merkill, 1 search Assistant. BOARD OF TRUSTEES OF THE MISSOURI BOTANICAL GARDEN President, EDWARDS WHITAKER. Vice-President, DAVID S. H. SMITH. Edwabd C. Eliot. G »bge C. Hitchcock. P. Chouteau Mapfitt. Edwabd Mallinckbodt. Leonabd Matiiu;\v3. William H. H. Peitus. Philip C. ca lain. John F. Shepi y. BX-OFFICIO MEMBERS; Engleb President of the Aca my of Science of St. Louis. David F. Houston, Chancellor of Washington Universit; HENBY W. Kit- Mayor of the City of St. Louis. Herman Mauch, Presldei of the Board Schools of St Louis. of Public Daniel S. Tuttle, Bishop of the Diocese of Missouri. ( ungham, Secietar Annals of the Missouri Botanical Garden Vol. 2 SEPTEMBER, 1915 No. 8 EHIZOCTONIA CROCORUM (PERS.) DC. AND R. SOLANI KUHN (CORTICIUM VAGUM B. & C), WITH NOTES ON OTHER SPECIES B. M. DUGGAR Physiologist to the Missouri Botanical Garden, in Charge of Graduate Laboratory Professor of Plant Physiology in the Henry Shaw School of Botany of Washington University The form genus Rhizoctonia was established in 1815 to include two parasitic species, both characterized in part by the production of a mat of violet mycelium investing the affected roots or other submerged members. The serious root diseases due to these organisms (later included in one species) have received consideration by many mycologists since that time. The demonstration is comparatively recent, however, that several important types of root and certain stem and other diseases of a variety of hosts are induced by two or more related species of this genus. The literature of Rhizoctonia diseases has grown enor- mously in the past fifteen years, yet some unnecessary con- fusion and difference of opinion exist regarding the two main species or groups of species and their distribution and rela- tion to disease in plants. This is in part due to the lack of comparative study and to the neglect or inadequacy of her- barium material. It seems well, therefore, to present a con- spectus of the investigations relating to this subject, and to include such comparative data as are available. In cooperation wfth:llri!F/:C: [Stewart of the New York (Geneva) Agricultural 1 Experiment fetation, I undertook, in 1898, a general s^ftdy V)J%t£j3 Y$&fop.\6fplhizoctonia, to plant diseases in Amefica*. * *Tnfe : jbiht 'investigation followed two Ann. Mo. Bot. (£/&».! *V<*i...* 2, 1916 ", . 5"S « ' • • • I (403) f 404 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 independent studies, one of a serious root disease of the sugar beet, the other of a destructive stem rot of the carnation. A preliminary report upon the investigations relating to R, So- lani Kiilm was published ('01), and it was arranged that in the further work one of us would undertake the morpho- logical, cultural, and taxonomic aspects of the study, and that the other would assume responsibility for all cross in- oculation and field work. Unfortunately for this purpose a change of position on the part of one of us and the demands of other work necessitated the abandonment of the plan as pro- posed. It is to be regretted particularly that the systematic inoculation experiments which had been carried forward for two seasons could not be continued and published. It is under- stood, however, that an extensive study in the relations of the culturable forms on different hosts has been carried forward both by cultural and inoculation experiments at the University of Illinois by Dr. George L. Peltier, who has already pre- sented a preliminary report ( '15), on the subject. It is mainly a general account of the diseases with notes on comparative morphology that I am able to include, but it is hoped that this may serve to clear up the more obvious difficulties and to suggest some problems requiring special investigation. The writer wishes to acknowledge the assistance, mentioned in the text, of many mycologists who have furnished material during the progress of these studies, and especially the cooperation of Mr. F. C. Stewart, who contributed many of the American hosts during the earlier studies. To Prof. E. A. Burt I am also indebted for suggestions. The Violet Root Felt Fungus, Rhizoctonta Crocorum (Pers.) DC. EARLY PATHOLOGICAL STUDIES The first mention of a plant disease which may be referred with certainty to Rhizoctonia as the causal agent is an impor- tant paper by Du Hamel: /17^>'jrjea;l before the Paris Academy. fungous dis In this paper he* "gives* a" careful description isease of \CffhhUsl sattiuiis-'' (iakiJii) occurrir. of a ' # (gaff .tan) occurring in France. His description 'o? general' pathological features 1915] DUGGAR — RHIZOCTONIA CROCORUM AND R. SOLANI 405 leaves little to be desired, and one cannot mistake the fact that he was discussing the disease, later known to be due to Rhizoctonia Crocorum. He does not describe the more minute morphological features, but discusses the macroscopic appear- ance of the mycelium and sclerotial stages with such com- pleteness that no doubt remains concerning the identity of the fungus. The illustration included would likewise confirm the description. He regarded the sclerotium, ' ' tubercule, ' ' as the fruit body of a fungus allied to the truffles, and to this special form of body, assumed to bear the organs of repro- duction, he gave the name ' ' tuberoides. ' ' He likewise deter- mined that a similar fungus is the cause of a disease found upon the roots of Sambucus Ebulus, Coronilla varia, Ononis spinosa, Muscari sp., and perhaps other plants. It was more than fifty years later that Fougeroux de Bon- daroy (1785), discussing primarily a disease of the saffron known as "tacon" gives further notes on the "mort du saf ran, ' ' recording the occurrence of this disease on asparagus when following (in the same soil) diseased crocus. After a further considerable lapse of time De Candolle (1815) made a careful study of the pathology of a similar alfalfa (Medicago sativa) disease in the vicinity of Mont- pellier, but known throughout France. This led to the estab- lishment of the genus Rhizoctonia as noted later. It is neces- sary to the pathological account to note here, however, that he recognized two species, R. Crocorum DC, primarily in- habiting the crocus, and R. Medicaginis DC, on the alfalfa and other hosts. He did not follow the development of the fungus on the saffron, where host characteristics render some- what obscure the appearance of the fungus ; and so for a long time the continuous violet felt of mycelium was associated primarily with R. Medicaginis. Among other diseases of the carrot and beets in Germany, Kiihn ( '58) found typical rots of these root crops, accom- panied in both cases by a red-violet mycelium with other characteristics indicating the alfalfa organism. He identified the fungus as R. Medicaginis and thus established the greater inmortance of Rhizoctonia diseases, and srreatlv extended the [Vol. 2 406 ANNALS OF THE MISSOURI BOTANICAL GARDEN range of the fungus. He found a somewhat similar disease of the potato, but clearly distinguished the fungus as another species, as further indicated in another part of this paper. Chief among those who extended our knowledge of the pathology and distribution of the violet root felt fungus was Rostrup ('86), who observed the fungus in Denmark and described its effects on various hosts. EARLY TAXONOMIC AND MORPHOLOGICAL ACCOUNTS The fungi belonging to the genus Rhisoctonia received attention taxonomically from the earliest mycologists. Brief references should be made to the works of some of those who have presented synopses of the genus or who have contributed to the solution of the problem regarding the taxonomic posi- tion of these fungi. Bulliard (1791) evidently based his description of species upon the observations and data of l)u Hamel and de Bondaroy; emphasizing therefore the sclero- tium as the fruit body, and believing it homologous with the truffle he gave to this fungus on Crocus sativus the name Tuber parasiticum. He contributed nothing further to the morphology of the species. Persoon (1801) did not accept Bulliard 's disposition of the fungus, but named it Sclerotium Crocorum, and gave a diagnosis which, while based on the observations of the earlier writers, did not confuse the sclero- tium with a true fruit body. De Candolle (1815 a ), in his first taxonomic discussion employed Persoon 's name for the fungus, and then, after giving the characteristics and parasitism of the species on alfalfa more careful attention, he established (1815, 1815 b ) the genus Rhizoctonia to include two species, R. Crocorum DC. on crocus and other hosts and R. Medicaginis DC. on alfalfa. It will be noted that he adopts Persoon 's specific name for the crocus fungus. De Candolle also considers a doubtful species, R. Mali, reported on apple. Nees (1816) placed the crocus fungus in Thanatophytum under the name T. Crocorum. Fries (1823) assigns Rhizoc- tonia to the Sclerotiaceae just following his extensive genus Sclerotium. It is important to note, since Fries' work has been 10161 DUGGAR RJIIZOCTONIA CROCORUM AND R. SOLANI 407 made the starting point for mycological nomenclature, that he designates three species in the following order, (1) R. Crocorum DC, (2) R. Medicaginis DC, and (3) R. muscorum Fr., also giving R. Mali DC among species ignota. The descriptions of the two species first mentioned leave no doubt that he is here defining the violet root felt fungus of crocus and of alfalfa. Moreover, Fries recognized Sclerotium Cro- corum Pers. as a synonym of R. Crocorum DC So far as has been ascertained no specimens of these species which he ex- amined are still in existence. Link (1824) excluded the doubt- ful forms, added a species R. strobilina, and otherwise left the genus as constituted by De Candolle. Duby (1830) in- cluded among the species Rhizoctonia Allii Graves, arranging the genus close to Sclerotium in the Scleroteae of Lycoper- claceae. Fries later included in this genus R. Batatas Fr. on Ipomoea Batatas from America. The most complete mycological account of the genus Rhizoc- tonia is that given by L. and C Tulasne ( '62). They reduce R. Crocorum DC and R. Medicaginis DC to a single species to which they apply a new name, significant of the appearance of the fungus, R. violacea Tul. This reduction to a single form was made after a most careful morphological study of the fungus in all stages. From the accurate descriptions and the excellent illustrations it is clear that they had under con- sideration material referable to the names above. The Tulasne brothers also refer to other species insufficiently known, as follows: R. Allii Graves, R. Batatas Fr., and R. (?) Mali DC « They were inclined to the view that the affinities of the genus would be found to be with the Ascomycetes, and, in fact, they considered certain minute cushions of hyphae, referred to in detail later, as immature perithecia. Successively, therefore, attention was drawn by mycologists (1) to the sclerotium as a fruit body (Du Hamel and Bulliard), (2) to the sclerotium as a sterile structure (Persoon), (3) to the strand-like habit of the mycelium (De Candolle), and (4) to the minute cushion- like sclerotia as suggesting perithecia (Tulasne, L. and C). [Vol. 2 408 ANNALS OF THE MISSOURI BOTANICAL GARDEN NAME, SYNONYMY, AND MATERIAL EXAMINED Since the investigations of the brothers Tulasne many mycologists have studied the violet root felt fungus on its various hosts, especially on crocus, alfalfa, and certain root crops. There is general, though not complete, agreement in confirmation of the view that the crocus and the alfalfa forms are identical, and that this species, R. Crocorum, occurs on numerous hosts. I shall indicate later some of the morpho- logical details in which the two forms agree and give other evidence supporting the view of a single species. For the present it is necessary to anticipate this evidence in order to state that until a perfect stage is definitely established, it would appear that the correct designation of the violet fungus is Rhizoctonia Crocorum (Pers.) DC. As noted above, the specific name applied by Persoon was adopted by De Candolle when he established the genus. This name, perhaps unfor- tunately, has priority over R. Medicaginis DC. in that it is mentioned first by Fries (1823). Though necessary, it may seem unwise to call the fungus R. Crocorum, inasmuch as it is far more widely distributed on alfalfa; and, furthermore, because its dicotyledonous hosts are more numerous. R. vio- lacea would be a most appropriate descriptive name, but it is obvious that this also would not conform to the rules. The following provisional synonymy has been collated: Tub (1791) Sclerotium Crocorum Pers. (1801), Rhizoctonia Crocorum DC. (1815), Rhizoctonia Medicaginis DC. (1815), Thanatophytum Crocorum Nees. (1816) Tuber Croci Duby (1830), Rhizoctonia Rubiae Dene. (1837), Rhizoctonia Dauci Rabenh. M859^ Rh (1862), Rhizoctonia Asparagi Fckl. [non Fr.] (1869), Hypochnus violaceus Eriks. (1913). The identity of Rhizoctonia Crocorum DC. and R. Medi- caginis DC. suggested by the brothers Tulasne ('62) and accepted by most taxonomists, has been confirmed by a study 1915] DUGGAR RHIZOCTONIA CROCORUM AND R. SOLAM 409 of all the material I have been able to examine, and there is included below a list of the material identified as Rhizoctonia Crocorum (Pers.) DC. Exsiccati: Rhizoctonia Medicaginis DC, Linhart, Fung. Hung. Fasc. 4: 400; Rhizoctonia Baud Rabenh., Rabenhorst, Herb. Mycolog. Fasc. 1 : 74. (Helminthosporium rhizoctonum Rabenh. ) ; Rhizoctonia Solani Kiihn, De Thuemon, Myc. Univ. Cent. 18 : 1797. European collections: (1) Material from Prof. Delacroix, Paris, 1901, as follows : on sugar beet ; on sugar beet, obtained by inoculation from diseased beet; on potato; on potato, by inoculation from affected beet ; on crocus ; on crocus, by inocu- lation from affected beet; on alfalfa; on Onobrychis sativus; on asparagus; and on asparagus, by inoculation from dis- eased beet. (2) On crocus from bulb gardens, Pithiviers, France, 1901. (3) From Prof. Aderhold, Proskau, Germany, 1899, on carrot and on root of young apple tree. (4) From Prof. Sorauer, Berlin, 1900, on potato and on asparagus. (5) From Herr Weigand, Helmitzheim, Bavaria, 1899, on alfalfa. (6) From Prof. v. Tubeuf, Munich, 1899, on sugar beet. (7) From Prof. Hartig, Munich, on roots of young coni- fer. (8) From Prof. Cugini, Modena, Italy, 1899, on alfalfa. (9) Material which the writer was able to obtain fresh near Munich, 1905, on sugar beet and alfalfa. In 1901 the writer was unable to find in the Kew Herbarium or in Paris any type material, and none was found in Mont- pellier in 1905. American collections: (1) From Mr. P. W. Graff, Man- hattan, Kansas, 1911, on alfalfa. (2) From Mr. F. D. Bailey, Laurel, Oregon, (sent by Dr. G. L. Peltier, Univ. of 111.) 1915, on potato. DISTRIBUTION In Europe the violet root felt fungus is in general widely distributed, but its occurrence now and then in epidemic form on some one host would appear to indicate some locality or race influence. On Crocus sativus the fungus has been re- ported from France chiefly; on asparagus, more frequently from France, Belgium, and Italy ; on Medicago sativa it would [Vol. 2 410 ANNALS OF THE MISSOURI BOTANICAL GARDEN seem to occur more commonly from southern France east- ward to Bavaria and Hungary and southward to the Mediter- ranean. No information is available with respect to its occur- rence in Russia. On the ileshy root crops and on the potato the fungus has often been reported from central France and Germany northward through Denmark, Norway and Sweden, and also on the sugar beet in Italy. In Denmark it appears to be found oftener on species of Trifolium than on alfalfa. The root felt disease is certainly not unknown to market gardeners and others throughout England, yet there are rela- tively few references to it in pathological literature. It would appear that Gtissow has observed the fungus in England, for in speaking of diseased tubers from a farm in Essex he says, ' ' They were covered with a dull reddish-brown web- bing, which was raised into numerous points, as if grains of sand were below it, ' ' but in view of his reference in the same article to the commoner potato fungus no definite statement should be made. Salmon's account ('08) of the disease of seakale, described as "a felted mass of violet spawn or my- celium," evidently refers to this species. In the United States R. Crocorum was first reported from Nebraska by Webber ( '90) on lucerne. He states that it was rare in the Nebraska flora at that time. Heald ('0G) lists the fungus as among disease-producing organisms prevalent in Nebraska during 1905. The record is as follows: "Root rot. Rhizoctonia violacea Tul. reported from a single locality: Platte County. Not common in that region. ' ' The complete observations made in 1906 were not reported until later, in which account, however, Heald ('11) fails to make note of Webber's earlier report of its occurrence. Freeman ('08) refers to the fungus as the cause of a well established disease of alfalfa in Kansas, and a specimen received by the writer in 1911 from that state indicates that it is identical with the European fungus. More recently it has been mentioned by Gandara ( '10), and the inference is that it is found on alfalfa in Mexico. The first occurrence on potato in America is from a locality in Oregon (Bailey, '15). No well authenticated instance of the occurrence of this fungus in South America, 1915] DUGGAR RHIZOCTONIA CROCORUM AND R. SOLANI 411 Australia, Asia, or Africa has come to my attention, yet the distribution of alfalfa growing throughout the world and the frequent interchange of seed might suggest that the distribu- tion of the organism may be found to be much more general than is reported. It should be mentioned that Shaw ('13) reports the fungus from India, but he has obviously been misled regarding the fungus concerned, as will be shown later. Du Hamel represented the violet root fungus as prevailing under a variety of soil conditions, but electing dry, gravelly, and acid localities. It is reported by the brothers Tulasne that while wet weather may give the fungus an advantage, still it is found in the driest situations permitting crop growth. In central Germany Kiihn's studies led to the sug- gestion that on root crops and potatoes it is found more fre- quently in low and stagnant places. Frank and Comes con- cur in this view. The writer was able to observe the fungus in the vicinity of Munich in 1905 and in the fields examined, it was found under conditions which appeared to be favor- able for the growth of the host. The very general occurrence of the fungus in southern Europe, especially in southern France and Italy, would seem to indicate that excessive moisture is not always an important factor. At the same time the fungus is of frequent occurrence in Scandinavia. It is not reported as one of the more serious diseases of any host in England. In the more humid regions of the eastern United States it is unknown, while two of the localities from which it has been reported are regions of lower humidity and lesser rainfall. HOST PLANTS AND GENERAL SYMPTOMS There is every reason to believe that the number of host plants for Rhizoctonia Crocorum is much greater than has been reported. The fungus has been observed upon many economic plants ; and it has been reported in the agricultural press of Europe as occurring upon a variety of weeds, but these references are not always definite. Eriksson has made some observations regarding the plants attacked when culti- [Vol. 2 412 ANNALS OF THE MISSOURI BOTANICAL GARDEN vated in soil from a carrot field known to bo infected, and the following weed hosts are noted: Stellaria media, Myosotis arvensis, Galeopsis Tetraliit, Erysimum cheiranthoides, Urtica dioica. This would indicate that a careful study of any epidemic would confirm the view that the number of hosts is consider- able. The following is a list by families of the host plants which have been reported in the more accessible literature : Pinaceae Abies pectinata Picea alba Picea excelsor Pinus Laricio Pinus montana Liliaceae Asparagus officinalis Crocus sativu; Lilium sp. Muscari sp. Narcissus sp. Tulipa sp. Urticaceae Ficus silvatica Humulus Lupulus Urtica dioica Polygonaceae Rumex crispus Chenopodiaceae Beta vulgaris Chenopodium album Caryophyllaceae Spergula arvensis Stellaria media Cruciferae Brassica campestris Brassica Rapa Crambe maritima Rosaceae Crataegus oxyacantha Pyrus Malus Leguminosae Anthyllis vulneraria Coronilla varia Medicago lupulina Medicago sativa Melilotus alba Leguminosae Onobrychis sativa Ononis spinosa Ornithopus sativus Phaseolus sp. Trifolium hybridum Trifolium pratense Trifolium repens Vicia Faba Geraniaceae Geranium pusillum Rutaceae Citrus Auranlium Vitaceae Vitis sp. Umbelliferae Daucus Carota Erysimum cheiranthoides Foeniculum vulgare Pastinaca sativa Oleaceae Ligustrum vulgare Convolvulaceae Convolvulus arvensis Boraginaceae Myosotis arvensis Labiatae Galeopsis Tetraliit Solanaceae Solanum tuberosum Rubiaceae Rubia tinctoria Caprifoliaceae Sambucus Ebulus Compositae Taraxacum officinale Sonchus arvensis Sonchus oleraceus 1915] DUGOAR RHIZOCTONIA CROCORUM AND R. SOLANI 413 The difficulty in giving an accurate list of hosts compiled from the literature is, however, a serious one, since one can- not be certain that all the observations are carefully made. Again, some mycologists do not distinguish the two species of Rhisoctonia here discussed; thus Salmon ('08), after describing an interesting disease of seakale with all the characteristics of R. Crocorum, goes on to refer to carnation stem rot, damping off, and other diseases as if they were induced by the same fungus, doubtless, however, intended to have reference to another related fungus. Eegarding the above-ground symptoms of affected plants, it may be said that they are not striking, and were it not for the characteristic dead area in the field it would not be an easy matter to designate slightly affected plants. Gen- erally, there is in alfalfa evidence of yellowing, sometimes marked chlorosis, while in beets and carrots there is merely a paler appearance of the foliage, followed by wilting. The critical period for affected alfalfa is usually about the time of the second cutting, and at this time considerable wilting may occur without preliminary indications of lack of health. In these main effects the disease is remarkably similar to the Texas root rot of cotton, alfalfa, and other plants. The un- mistakable symptom is the relatively sudden dying of the plant affected. The disease is generally though not necessarily fatal. Even a plant so susceptible as the alfalfa may recover from early injuries, usually with the loss of the tap root. Under cer- tain conditions the disease incites the development of ad- ventitious roots, — which may be a factor in recovery. The progress of the disease in the field is radial, and during the first year especially, circular dead areas mark its presence. The spread of the fungus during the season may be from a few feet to several rods. After the first year or two, con- siderable areas irregular in outline may be involved. MYCELIUM AND SCLEllOTIA It would be difficult to confuse the mycelium of the violet root felt fungus with any other species, for when one is [Vol. 2 414 ANNALS OF THE MISSOURI BOTANICAL GARDEN familiar with it in the different stages of development it is at all times an organism with striking characteristics. Such differences in appearance as may be found in comparable stages on the various hosts may be regarded as causally re- lated to the host substratum, or, at least they may be so re- garded until adequate morphological differences or contrast- ing physiological relations are estab- appearance of lished. The general affected roots of asparagus, carrot, beet, or alfalfa are well expressed in some of the common names applied, such as red root, root felt disease, violet fungus, etc. With sufficient time for abundant growth the fungus completely in- vests the root or root system with a mantle, weft, or mat of hyphae of characteristic color. In the early stages of growth on the root the mycelium is pale buff to violaceous, but when the root is completely in- Fig. 1. Rhizoctonia, Cro- vested, the mycelium is red-violet to h Jl violet-brown, and always violet- brown with age or when densely matted. The numerous small darker papillae or " minute sclerotia" in the mantle of mycelium are in reality cushion-like mycelial bodies described later. In the following description the writer will not attempt to follow all changes in the development of the various mycelial conditions, but will endeavor to give briefly those develop- mental features characteristics which may be applied to most herbarium ma- terial. For further morphological details the accounts of L. and C. Tulasne ('62) and Prillieux ('91) should be consulted. The external, general hyphae are more or less different in form and appearance with age. The younger hyphae are usually dilutely violaceous with a pigment which may be decolorized by the application of acidulated water. The pro- of greatest interest and those diagnostic 1916] DUGGAR RHIZOCTONIA CROCORUM AND R. SOLANI 415 toplasm is dense towards the tips of branches and vacuolated farther away. The hyphae are somewhat flexuous, branched (sometimes closely), with the branches arising at right angles to the main hypha, and with a partition wall laid down at .1). With age the hyphae become the branching is to not over 10 n distant rigid, someAvhat less in diameter, 4-8 n distant, and these branches readily break off at the first par- tition wall to" 2). At the point of union the diameter is uniform with the main hypha. The partition walls are distant, Fig. 2. Rhizoctonia Crocorum: Mature root-investing hyphae. often 120-200 n apart. The walls now possess the violet- brown pigment and in the lumen little or no protoplasm is observable. The internal mycelium is likewise branched, septate, often ssociated loose strands between the cells or g them In the early stages of the disease, so far as reported, these internal hyphae are nearly colorless ; Prunet reports that there are sometimes areas of brown mycelium in the attacked tissues, and this I find particularly true of asparagus. The internal hyphae are generally of less diam- eter than those constituting the external mat. Disregarding for the time the small cushions already men- [Vol. 2 416 ANNALS OF T1JE MISSOURI BOTANICAL GARDEN tioned, the hyphae constituting the external mantle may be uniformly distributed, as is the case usually when the fungus attacks fleshy roots or tubers, or they may also form a num- ber of aggregates having the appearance of loose or root- like strands. The strands are developed later rather than early in the progress of the disease. They are conspicuous on such hosts as alfalfa and sainfoin. These strands course along the whole root system; they also pass out into the soil, apparently beyond the minutest rootlets, and doubt- less attack plants in the vicinity. Upon the larger strands sclerotia may be formed, and thus the sclerotia are connected with the mantle of hyphae. Infection Cushions. — Small stromatic bodies distributed amongst the hyphae were noted by several of the early ob- servers. Kiihn ('58) calls special attention to them on the carrot and the potato. The brothers Tulasne ('62) studied and described them in some detail and came to the conclusion that these were the early stages in the development of the perithecial form. Search for the reproductive phase was in this way transferred from the sclerotium to the bodies in question. Sorauer ( '86*) among others accepted the view of the perithecial nature of this structure. Prillieux ( '91) seems to have been the first to point out that the ' ' corps miliaires, ' ' as he termed them, are in reality special mycelial cushions having the important function of effecting the penetration of the host. He regarded them as the main, if not the sole, seats of tissue invasion, and his studies included a comparison of these bodies and of the penetrating strands in alfalfa, sugar beet, and crocus. After mentioning these cushions as one type of sclerotia, Prunet designates them more specifically as minute "corps noiratres," .2 to 1.2 mm. in diameter with a brown hyphal cortex and a colorless medullar. He indicates that these as well as the larger sclerotia send out filaments which enter the soil and extend the fungus. These bodies have also been figured by Bailey ( '15) in the case of the occur- rence of the fungus on the potato in Oregon and particularly well by Salmon and Crompton ('08, pi. 25). The writer is of the opinion that Prillieux 's notion is in general correct, 191 5 J DUGGAR RHIZOCTONIA CROCORUM AND R. SOLANI 417 and while they are not the only means of penetration they are most important in this connection. The hosts upon which the writer has had the opportunity to examine the infection cushions in best condition are alfalfa, carrot, and asparagus. The cushions are distributed over in- fected roots, often 1 mm. apart in alfalfa, .5 mm. in carrot, and 3 mm. in asparagus. The external hyphae are for the most part similar to those of the general mycelium, but there occur also branches in which the cells are short and swollen, sometimes resembling a short chain of spores. This form of hypha may have given the suggestion of a conidial stage (see Kuhn ('58), Sorauer ('86), and others. The medullary portion of younger cushions is made up of finer, almost colorless hyphae, and it is this type which enters — strand-like — the cortical tissues of the root, destroying particularly the cambium and younger phloem regions. In the later stages of development it will be found that the cushions seem to extend consider- ably into the cortex, and more of the hyphae are colored. In this connection it is well to call attention briefly to some gross changes in the affected roots. By the time the host (alfalfa) reaches the critical stage, the bark slips readily from the root. The disintegration may continue further, however, through the spread of the fungus to the medullary rays and all other parenchyma, so that the root shreds or crumbles when lifted. The late stages of destruction may be assisted by saprophytic organisms. It is difficult to determine if the fungus continues its growth for a short time after the death of the root. At any rate, the fungus rapidly disappears with the further decay of the roots. In the case of asparagus the cushions are largely super- ficial and the main affected tissues are beneath the shell of thick-walled cells constituting the periphery of the host. In the carrot the invading strands are large, and the host cells in the vicinity rapidly collapse and darken. I have been for- tunate in obtaining affected asparagus roots at intervals after the disease had run its course. In no case could any evidences of spore forms be found which gave promise of genetic con- nection. On the contrary, the fungus gradually disappears, [Vol. 2 418 ANNALS OP THE MISSOURI BOTANICAL GARDEN first the mantle of mycelium, and then the cushions, so that when the root is reduced to a mere shell there are only vestiges of the cushions remaining. Sclerotia. — The true sclerotia are flattened or rounded bodies varying in diameter from a few millimeters to several centimeters. When mature they are of a deep violet-brown Fig. 3. Rhizoctonia Crocorum: covering the surfaces of the large "infection cushions." Cells characteristic of the tufted growth sclerotia and to a certain extent of the darkening further in. Among the and are thickly clothed with a persistent velvety felt, ex- ternally of the same color as the root-investing hyphae, but surface hyphae of the sclerotia as well as of the " infection cushions" are found chains of enlarged cells (fig. 3) quite distinct from the en- larged cells of R. Solani. The sclerotia, as noted previously, are always connected with the root felt by large hyphal strands. In the saffron disease the sclerotia are formed both in contact with the shriveling bulb and also in the adjacent soil. On affected alfalfa roots they often occur below, and in the angles of, the larger branches, but often one finds no sclerotia in immediate contact with the host. In connection with diseased carrots, beets, and potatoes, they are not so frequent, unless perhaps they are then formed at greater 19151 DUGGAR RHIZOCTONIA CROCORUM AND R. SOLANI 419 distances from the plant. Most herbarium material, unfor tunately, with include sclerot ception of crocus specimens, does not In a sclerotium consists of f compact tissue made up of cells often considerably branched and sometimes curiously lobed (fig. 4). Fig. 4. Rhizootonia Crocorum: a, from a section of a large sclerotium; b, extreme forms of cells isolated from a macerated sclerotium. SUGGESTIONS REGARDING THE PERFECT STAGE It has been noted that Du Hamel and other early observers stated that the affinities of the violet fungus were with the truffles. Per Sclerotium. Fries, and others placed the genus near Tulasne considered the small sclerotia as prob- ably a stage in the development of (pyreno- m This suggestion of Tulasne has apparently in- fluenced many mycologists, and a search in this direction the perfect stage present time. Fu« has continued practically until the el suggested that Lanosa nivalis Fr. be considered the first or conidial stage of this fungus and he believed that the minut sclerotia or penet cushions gave rise during the latter part of the season to pycnidia. With the more complete disintegration of the af- fected tissues he ted development of stage, and this fungus he called Byssothecium circinans (Lep tosphaeria circinans (Fckl.) Sacc, Trematosphaeria circinam (Fckl.) A\ It will be noted that Winter regarded this t [Vol.. 2 420 ANNALS OF THE MISSOURI BOTANICAL GARDEN view of the genetic relation to Rhizoctonia as improbable; and Saccardo, who at first accepted the relationship, subse- quently changed his opinion. Prunet ('93) states that he made certain inoculation experiments from which he was con- vinced that Fuckel was correct; but we possess no indica- tions as to how these experiments were conducted. The writer in 1899, at Leipzig, germinated the spores of Lepto- sphaeria circinans and obtained a mycelium bearing no re- semblance to the Rhizoctonia hyphae. The idea that Lepto- sphaeria constitutes a perfect stage of the Rhizoctonia has had no support recently, although Comes ('91) incorporates extreme form in his treatment of 5 Rostrup ( '86) found in the spring on the old roots of af- fected plants a pycnidial stage which he considered to be con- nected with the Rhizoctonia hyphae; and on the old roots of Ligustrum he found reddish filaments and scattering peri- thecia; the latter he identified as a species of Trichosphaeria. His assumption, however, has received no encouragement. When Hartig ('80) discovered a Rosellinia as the perfect stage of his Rhizoctonia Quercina there was a temporary re- vival of interest in the quest for one of the Ascomycetes as the perfect stage of R. Cvocorum. Frank ('97) reported observing the violet fungus on the grape, and associated with it he found a species of the The- Jephoraceae. This he regarded as the perfect stage, and to the fungus he applied the name Thelephora Rhlzoctoniae. This observation has failed of confirmation. Eriksson ('13) has recently presented an extension of his earlier account ('03 a ) of diseases produced by Rhizoctonia, and in this he records a new "Hypochnus," H. violaceus (Tul.) Eriks. as the perfect stage of "Rhizoctonia violacea, Tul." In this he was stimulated by the observations of Rolfs ('03) and others in America, and Pethybridge ('11) in Ire- land, on the occurrence of the basidial stage (Corticium vagum B. & C. or Hypochnus Solani Prill. & Del.) of Rhizoc- tonia Solani Kiihn, resulting in a reexamination of some ma- terial of the violet fungus on roots and stems of certain wild plants. This material had been preserved in alcohol thirteen 19151 DUGGAR — RHIZOCTONIA CROCORUM AND R. SOLANI 421 years earlier. The result of his study is reported as follows : "D'apres ces renseignements, il faut — du moins pour ce qui concerne les formes du champignon qui envahissent les Car- rottes — considerer comme resolue la question tant debattue de savoir a quel groupe rapporter le mycelium sterile connu sous le nom de Rhizoctonia violacea. Dans ce qui suit, je vais in- diquer le nom scientifique qu'il faut donner, ainsi que les car- acteres diagnostiques du champignon autant que j'aie pu en juger sur les documents conserves que j'avais a ma disposition." On the basis of these observations he creates the Hypochnus mentioned. No adequate diagnosis is given, but the im- portant part of the account is as follows : "Ensuite le champignon forme autour des tiges de la meme plante ou d'autres especes de plantes immediatement au-dessus du sol, une enveloppe annulaire, membraneuse, d'un rose tendre, qui, montant souvent sur les tiges jusqua une hauteur de 5 a 15 mm. et s'etalant parfois sur la surface du sol comme une feuille toute mince, produit des basidiospores. C ? est le stade Hypochnus/' This apparently refers to material on Stellaria media, Myo- sotis arvensis, Galeopsis Tetrahit, Erysimum cheiranthoides, Urtica dioica, and Sonchus arvensis, which hosts he would regard as harboring the Hypochnus stage of that form of the violet fungus attacking the carrot, and for this reason the names just given appear in the list of hosts. In the writer's opinion he properly considers it remarkable that the fructification stage should attack hosts other than prod In view of the character of the material, the incompleteness of the account, and the pos- sibility of confusion with Corticium vagum B. & C. it would appear necessary to await confirmation of the observation that a Corticium (Hypochnus) may represent the perfect stage of the fungus here discussed, although, reasoning from the apparent relationship of this species to R. Solani, a Corticium stage might well be assumed. The writer has been unable thus far to secure any of the material mentioned. In a footnote Eriksson expresses himself thus: " Quant la Rhizoctone de la Luzerne, je suis norte a croire. d'anres 1 [Vol. 2 422 ANNALS OF THE MISSOURI BOTANICAL GARDEN observations de cette annee (1912), quelle doit etre rapportee a un groupe d 'Ascomycetes. " This suggestion is both in- teresting and surprising since Eriksson adopts the Tulasnes' name for the Rhizoctonia on carrot and this would seem to concede the identity of the carrot and alfalfa forms. It is also in a measure inconsistent with his inoculation results, as reported later. 1 CROSS INOCULATION AND CULTURAL STUDIES The amount of cross inoculation work yet reported is not considerable, and for this, doubtless, the inability to cultivate the organism is largely responsible. Throughout the early literature numerous indications are offered showing that fol- lowing a severe outbreak of the disease on any crop, it may appear on susceptible plants grown in the affected area — ob- servations which tend to establish the identity of the fungus on different hosts. Among later observations may be men- tioned those of Giintz ('99) who records that in a field where alfalfa and red clover had been seriously affected, beans, potatoes, and tuberous artichokes were planted ; the potatoes subsequently developed the disease in serious form, and the other plants showed indications of its presence. In England it is reported (Bd. of Agr., '06) that potatoes are affected by the violet felt fungus, especially when following alfalfa ; and under similar conditions the fungus appears upon clover, car- rots, beets, and mangolds. Eriksson ('13) undertook some cross inoculation work em- ploying, in zinc cylinders, soil from diseased carrot fields (eight cylinders) in contrast with soil taken from areas free from the disease (two cylinders). At the same time, to the diseased soil he added pieces of carrots affected by the fungus. The cylinders were permitted to stand over winter l Since obtaining proof of this paper I have received from Prof. Eriksson an advance reprint of his paper, "Fortgesetze Studien tiber Rhizoctonia violacea DC." Arkiv for Bot. 14 (Art 12) : 1-31. f. 1-18. 1915. It is impracticable to include here a full discussion of this paper. It is necessary to state, however, that he treats at length Rhizoctonia M edicaginis DC. and R. Asparagi Fckl., and includes inoculation experiments indicating form differences. After germinating the spores of Leptosphaeria circinans he comes to the conclusion that, in spite of his earlier work on Hypochnus violaceus, the pyrenomycete mentioned is the perfect stage of R. Medicaginis. Prof. Eriksson has also furnished material of R. Asparagi and of the Leptosphaeria. 1915] DUGGAR RHIZOCTONIA CROCORUM AND R. SOLANI 423 and the following spring were planted to several varieties of carrots, to beets, mangolds, red clover, and alfalfa. At the time of harvest, the carrots were all more or less severely- affected, while the sugar beets and alfalfa showed very light attacks, and the clover none at all. Continuing the work in subsequent seasons he obtained evidence in one case — that of the sugar beet — pointing to an increased virulence of the fungus with adjustment to that host. On the contrary, in the second year the alfalfa exhibited greater resistance, thus rendering a decision as to the existence of physiological races hazardous. He also reported, that on placing diseased soil and diseased carrots in a box in which various weeds were permitted to grow, the fungus appeared on eight species of weeds (representing several families), apparently a consider- able proportion of those present. This also would seem to discourage the idea of marked host specialization. Attempts to cultivate the violet fungus on artificial media have been made by several investigators without success. While in Leipzig, 1900, I obtained particularly good material on alfalfa from Bavaria. Dilution cultures were attempted both on various kinds of agar and on gelatin, but no growth of the fungus was secured in any case. Further trials were made with material from France in 1902, and again upon re- ceiving comparatively fresh material from Kansas in 1911. Bailey ('15) reports an endeavor to cultivate the organism in Oregon, also without success. It is quite possible that special conditions are essential to its growth in artificial cul- ture, but we should not assume that it is incapable of growth in this way. It would appear that the presence of contami- nating organisms is not the sole cause of the difficulty, since isolated hyphae in the dilution cultures remain free from the growth of contaminating organisms, and yet themselves fail to develop a colony of growth. It will be recalled that At- kinson 1 found difficulty, but ultimate success, in growing Ozonium omnivorum (Lk.) Shear, the cause of the south- western root rot of cotton. The writer also found that this organism is not readily cultured, but obtained a satisfactory iBot. Gaz. 18: 16-19. 1893. [Vol. 2 424 ANNALS OF THE MISSOURI BOTANICAL GARDEN growth on cotton decoction starch paste in 1902. Since in general pathology and physiology the cotton Ozonium and the violet Rhizoctonia have much in common, a further careful investigation of their life relations would doubtless yield interesting results. PREVENTION' AND CONTROL Relief measures respecting the violet fungus are very largely limited to the practices of good culture, good drain- age, and sanitation. The early pathologists have generally recommended pulling up diseased plants and burning them. It is well to point out, however, that after a careful examina- tion of the distribution of the fungus on the smallest fibrous roots, it has been found to invest these to a considerable depth in the case of alfalfa, and therefore a very small meas- ure of security may be expected unless one carries out this recommendation in a far more thorough manner than is practicable in the field. The further suggestion has been made that where the diseased areas are few, small, and clearly defined, trenches may be dug to prevent the further spread of the disease; but if this should prove feasible under any con- ditions, it would be advisable only in connection with a thor- ough disinfection of the isolated areas by formaldehyde or sulphuric acid — the former disappearing from soil in time, and the latter being easily neutralized by liming. The rota- tion of crops is undoubtedly desirable, but complete immun- ity from the disease cannot be expected if we may trust the statements of Du Hamel and other observers to the effect that the fungus may remain alive in the soil for periods of from three to twenty years. The fact that many hosts are affected also complicates the practice of rotation. The Common Rhizoctonia, R. Solani Kuhn (Corticium vagum B. & C.) EARLY STAGES In addition to his discussion of the violet Rhizoctonia on beets and carrots Kuhn ('58) described a disease of potatoes, of which the causal organism was recognized as a species of 1915] DUGCAR RHIZOCTONIA CROCORUM AND R. SOLAN I 425 Rhizoctonia differing notably from the violet organism, and to this potato fungus he gave the name R. Solani. The life history of the fungus and the symptoms of the disease induced were very imperfectly known at the time, so that the descrip- tion could not be complete. As a result, those who subse- quently discussed the genus Rhizoctonia have sometimes recognized R. Solani, while others have referred the organism to R. Crocorum (R. violacea), and still others have assumed that R. Solani Kiihn was also the cause of another disease of beets and of carrots mentioned by Kulm without identifying the causal organisms. After a study of certain diseases in America induced by Rhizoctonia, I was keenly aware of this confusion, so when opportunity presented itself in the winter of 1899-1900 I conferred with Professor Kiihn regarding those diseases, and also endeavored to obtain satisfactory specimens of the fungi. There has been no earlier oppor- tunity to utilize the information obtained in connection with a general discussion of the genus. Kiihn laid special stress upon a scab ("Schorf oder Grind," later termed "Pockenkrankheit") of potatoes, sometimes followed by deeper seated injuries and decomposition ("als J\^ Raude und Kratze bezeichnet"). The symptoms are clearly w those that we now know as one type (cf. McAlpine, '12) of ^ the potato diseases ascribed to R. Solani Kiihn (Corticium vagum B. & C). It has been noted that the fungus was not so well described as might be wished, and the spores men- tioned were evidently those of contaminating organisms, or else the oval cells of the tufted stage of the fungus ; but when we use in connection with this general description Kiihn 's comparison of this plant with the violet fungus (Kiihn, '58, p. 248) it is convincing that the fungus on the potato which he had under consideration was not Rhizoctonia Crocorum. The sclerotia were also inadequately described and figured. With reference to that point, however, Professor Kiihn stated that while a common form of the fungus on the tubers con- sisted of irregular superficial sclerotia, this form did not lead to serious consequences and therefore received less attention from him. Material of this superficial sclerotial stage was .RARY '' * L SC*0 O v [Vol. 2 426 ANNALS OF THE MISSOURI BOTANICAL GARDEN furnished the writer by Professor Sorauer in 1900 (for a photograph see Duggar, '09, p. 477, fig. 219), and, subsequently, from other points in Germany. It is clearly the "black speck" form of the disease now generally recognized. Professor Kiihn also identified cultures of the American fungus on sugar beets (Duggar, '99) as very close to, if not identical with, his R. Solani. In 1858 Kiihn was obviously unaware of the fact that the violet fungus also occurs on potato in Germany ; and, in fact, he told me in 1900 that it was subsequent to 1858 when he first collected specimens of the violet fungus on this host. "The violet fungus produces no serious epidemics of the potato in Germany," he declared. Professor Kiihn was un- able to locate type material of R. Solani, and such material is doubtless unavailable. Before presenting still other indi- cations pointing unmistakably to their identity, I shall proceed on the basis that it is correct to refer the sterile stages of the commoner American Rhizoctonia on potato and other plants to R. Solani Kiihn, and once studied comparatively there can be no confusion of this plant with R. Crocorum (Pers.) DC. A disease of carrots was also described by Kiihn with which no fungus was positively associated. The indications are in- sufficient to determine whether this was a fungus or a bacterial disease. So far as the writer is aware no disease of carrots in Europe due to R. Solani has since been reported, though in 1900 Professor Kiihn stated as his opinion that carrots as well as beets in Germany were affected by a fungus similar to R. Solani. The violet root felt fungus was clearly distinguished by Kiihn ( '58, see pp. 235-237, 243-249) in its occurrence on both beets and carrots. It is not possible to mistake his statements in which the organism on these hosts is referred to Rhizoc- tonia Medicaginis DC." Moreover, he nowhere suggests the combinations R. Baud Kiihn and R. Betae Kiihn, which later crept into the literature of the subject. This fact makes it difficult to understand the nomenclature employed by Eidam ( '87) and Comes ( '91). In discussing a beet disease prevalent in Germany, Eidam refers the organism to Rhizoctonia Betae Kiihn. He gives a description of the disease and of the fun- 1915] DUGGAR RHIZOCTONIA CROCORUM AND R. SOLANI 427 gus, including its growth on culture media. It is clearly the beet disease now well known in America, and of which the causal fungus is referred to R. Solani. Kiihn did describe the symptoms of another disease of beets, and this last bears every indication of being the heart rot later known to be due to Phoma Betae (Phyllosticta tabifica), much discussed by Frank and others. Kiihn 's discussion of this other beet disease has been interpreted, also, in the way I have indicated by Prillieux and Delacroix ('91) and others outside of Germany. In my conference with him, Professor Kiihn stated that the only Rhizoctonia diseases of beets and carrots which he knew in the vicinity of Halle in 1858 and earlier were those due to the violet fungus, and of these he exhibited specimens having the usual characteristics. From the evidence at hand, therefore, the Rhizoctonia disease of beets described by Eidam was new on that host. It would seem, then, that Eidam is the authority for the combination R. Betae, which he attributes to Kiihn. In any case it be- comes a synonym of R. Solani Kiihn (Corticium vagum B. & C). In discussing the Rhizoctonia disease of potatoes in Europe Sorauer ('86) describes unmistakably the "black speck" or sclerotial form of the fungus, and while he, like many others, assumed that it would be found to belong among the Ascomy- cetes, it is obvious that the characteristics of this stage of Kiihn 's fungus were well recognized. Among the forms of Rhizoctonia which he enumerated and discussed Comes ('91) includes R. Baud Kiihn, and R. Betae Kiihn. In his discussion of the first-named he reviews Kiihn 's account of the violet fungus on carrots, already mentioned; but in the account of R. Betae Kiihn he evidently refers both to Kiihn 's account of the heart rot of beets and to the Rhizoc- tonia disease of this host described by Eidam. Pammel ( '91) was the first American pathologist to report in this country a disease now known to be caused by R. Solani. He, however, followed Comes and Eidam in referring to the fungus causing the beet rot as R. Betae Kiihn. Atkinson ('92, '95) studied a "sterile" fungus causing sore [Vol. 2 428 ANNALS OF THE MISSOURI BOTANICAL GARDEN shin or clamping off in cotton, and ascertained that the same fungus was commonly associated with, and capable of, induc- ing damping off of various seedlings in the greenhouse. Duggar ('99) also referred to the beet rot fungus in Amer- ica as Rhizoctonia Betae Kiilm, following Comes, and was able to determine that this beet fungus was identical morpho- logically (mycelium and sclerotia) with the damping off fun- gus found by Atkinson. The characteristics of the two organ- isms in culture were also identical, both forming on certain media a rich mycelium and finally numerous flaky or tufted centers of growth, some of which become irregular, often crust-like, sclerotia. Neither on affected seedlings nor on beets were sclerotia ordinarily produced (compare, however, Edson, '15, pi. 23). Subsequently, Duggar and Stewart ('01) reported that several types of disease, on a variety of hosts, including the potato, were induced by Rhizoctonia, The account given was intended to be merely preliminary, and for this reason a few words of explanation are necessary. The account referred to did not (perhaps unfortunately) explicitly indicate that, as far as the studies had progressed, there was evidence that the organism, or forms of the organism (except in the case of the form on rhubarb, referred to later) exhibited morpho- logically and in culture the characters of the beet rot and damping off fungus. The authors were likewise convince ' after a study of European material of Kiihn 's fungus on the potato, of the identity of the American and European forms on this host. Cultural studies were being carried forward with Rhizoctonia Solani from many hosts, since there was the possibility of establishing definite forms or races, of find- d the perfect stage, and of disco\ A specimens of the violet root felt fungus on various hosts had been obtained by one of us, and it was intended to include final paper a general account of rt This failure to designate the form with which we worked has doubtless led to some misunderstanding (see Prillieux '97, Eriksson '13, p. 17). However, in a more recent account (Duggar, '09, pp. 477-478), it will be seen that the diseases 1915] DUGOAR RHIZOCTONIA CROCORUM AND R. SOLANI 429 discussed are ascribed to R. Solani {Corticium vagum B. & C). DISTRIBUTION Rhizoctonia Solani is distributed throughout the United States and Canada. There is every reason to believe that it exists as a saprophyte in most arable soils, and under certain conditions may attack many species of plants. It is perhaps most frequently noted as a damping off disease in green- houses and seed beds, but this occurrence may be explained by the fact that here the conditions are probably more con- ducive to the pathogenicity of the fungus. On the potato it is likewise wide-spread, although, as noted later, the eco- nomic importance of the diseases induced varies in different sections of the country, probably in accordance with climatic and soil conditions. In all potato-producing states and re- gions it is a well-known disease. On the sugar beet it has been observed in many states. The fact that it is an important disease of one crop or another in every section of the country is alone sufficient indication of its general occurrence. Rhiz- octonia has been mentioned in Brazil by Potel ('00), but it is not clear to which species he refers. It is rather surprising to find that R. Solani has received relatively little attention in Europe. Although recognized as inducing a disease of the potato widely distributed in central Europe, and occasionally reported on the beet, yet little care- ful work has been bestowed upon the fungus. Eriksson ( '13), seems to be unfamiliar with the fungus in Sweden. On this account we can gain no incidental information regarding R. Solani as a result of his extensive studies of the related spe- cies in that country. The following will express his attitude regarding R. Solani: "II parait tres douteux, du moins si l'on en juge d'apres les descriptions et les figures donnees, que les nouvelles formes de la Rhizoctone sterile signalees dans ces derniers temps par B. M. Duggar et F. C. Stewart sur une quantitc de plantes differentes en Amerique (* * *) soient vraiment identiques aux formes du Rhizoctonia violacea qui ravage l'Europe." We have very little data regarding its occurrence in other sections of continental Europe, although from conference [Vol. 2 430 ANNALS OF THE MISSOURI BOTANICAL GARDEN with Prof. Delacroix in Paris (Nov. 28, 1901) and from an examination of material furnished by him I learned that it is not uncommon throughout France on the potato. It will be recalled that the perfect stage was described by Prillieux and Delacroix ('91). Judging from the amount of the black speck disease observed on the potato in the markets of various cities in southern Europe during 1905- '06 the writer would infer that it is of more frequent occurrence than is reported. Pethybridge ('11) finds the fungus (including the Corticium stage) well distributed in Ireland, and it is reported from other parts of Great Britain. McAlpine ( '11) has reported this fungus on the potato from several points in Australia, and he states that it occurs upon a variety of economic plants. Since it has proved a serious disease in very few localities, it receives little attention, and is therefore freely disseminated by commercial intercourse. It is also known in New Zealand and Japan. The investigations of Shaw ('13) suggest that Rhizoctonia Solani may be an important disease-inducing organism in some of the more humid regions of India. Reference is made later (pp. 448-450) to the fact that he has obviously misap- plied this name, however, and also that other confusion has resulted. In spite of this, it seems certain that he has ob- served all stages of the fungus. TYPES OF DISEASES INDUCED, SYMPTOMS It is not my purpose to attempt a complete description of the more important diseases caused by this species, yet suf- ficient will be included to indicate the main types of diseases thus far investigated, their general distribution, and their striking pathological relations. By types of disease, I have reference to general effects or symptoms. The effect of the fungus upon the stems may occasion a different appearance from its action upon the root, and thus there arise the differ- ent types referred to. "With respect to penetration and action up- on the cell the behavior of the fungus may be the same in all cases. Moreover, as a result of the primary injury, second- ary effects may occur, and sometimes such secondary phe- 1915] DUGOAR RHIZOCTONIA CROCORUM AND R. SOLANI 431 nomena may be so striking in appearance as to dominate the primary injuries or lesions. For convenience we may arrange the types of disease in the following categories: (1) damping off, (2) stem rot, (3) root rot, (4) leaf rot, (5) scab, and (6) such secondary effects as rosette, little potato, and leaf roll. Since more than one type of disease may occur upon a single host, and especially since one form of the disease may grade into another, it will be more practicable to discuss these under the following captions: (1) damping off, (2) potato diseases, (3) rot of fleshy roots, (4) stem and root rots of herbaceous plants, and (5) fruit and leaf injuries. DAMPING OFF It would appear that the first mention of a disease of seed- lings caused by Rhizoctonia is that of beets, recorded Eidam ('87), although he gives no complete account of the evidence. It is preferable to date our knowledge of damping off diseases caused by Rhizoctonia from the work of Atkinson ('92), who studied particularly sore shin of cotton, but he also found the "sterile" fungus to cause damping off of seedling beets, radish, lettuce, Qgg plants, cabbage, and other plants in the forcing house. The later identification of the fungus concerned (Duggar, '99) and its association with the damping off of various plants (Duggar and Stewart, '01 ) was only the beginning of the observations which have now served to direct our attention to the vast importance of this fungous disease throughout the United States both in the greenhouse and in the outside seed bed. Among numerous instances in which damping off has been reported due (or in all probability due) to this fungus may be noted the following: (1). It has been found as a source of serious injury to ginseng in the seed bed (Van Hook, '04; Whetzel and Rosenbaum, '12). (2). Tobacco seedlings are so frequently injured that soil treatment has received special consideration in the case of this crop (Selby, '04; Cook and Home, '05). (3). As a damping off disease of cotton (sore shin) it occurs not only in America but in Africa (Balls, '05, '06) and possibly in India (Shaw, '13) as well. (4). Tomato 432 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vor.. 2 seedlings seldom attacked by Pythium have been found to succumb to Rhizoctonia in Louisiana (Edgerton and More- land, '13 ). (5). Alfalfa seedlings have been reported sus- ceptible in one instance (Stewart, French, and Wilson, '08). (6). Seedlings of various species of conifers from a few days to nine weeks old have been reported attacked in several in- stances (Hartley, '12, Clinton, '13). The majority of the instances reported above were under normal seed bed or field conditions. Many other cases of the damping off of seedlings might be included where seeds are grown in crowded condition in moist greenhouses. Again, damping off of cuttings by Rhizoctonia is now a well-known phenomenon in the propagating house, and special precau- tions are taken with respect to drainage and moisture in order to reduce the injuries to a minimum. It is safe to assume — since the fungus seems to be found in practically all soils that it is in general the worst enemy of seedling plants. In fact, it may be anticipated that under conditions favorable for the fungus the damping off of seedlings of numerous species may be anticipated. So far as the writer has been able to ascertain there has been no report of the damping off of mon- ocotyledonous plants under normal seed bed conditions. While Rhizoctonia Solani may perhaps induce damping off in innumerable species regarding which observations are lacking, some of the host plants which have come to the writ- er's attention as particularly susceptible are the following: lettuce (Lactuca sativa), celery {Apium graveolens), beet {Beta vulgaris), cress (Lepidium sativum), tobacco (Nico- tiana Tabacum), balsam (Impatiens balsamina), snapdragon (Antirrhinum ma jus), cotton (Gossypium spp.), cucumber (Cucumis sativus), squash (Cucurbit a spp.), sunflower (Heli- anthus annuus), carrot (Daucus Carota), radish (Raphanus sativus), and phlox (Phlox Drummondii). Since the phycomycetous damping off fungus Pythium has been known to pathologists much longer, and prior to 1895 was practically the only fungus to which this type of disease was ascribed, it is probable that much damage due to Rhi- octonia has been ascribed to Pythium. Moreover, unless 1915] GGAR — RHIZOCTONIA CROCORUM AND R. SOLAN I 433 examined microscopically, there are no symptomatic differ- ences between the effects of the two organisms. Seedlings affected exhibit symptoms somewhat different with age. The youngest seedlings of all delicate plants show what may be called the usual damping off characteristics. Near the base of the stem an hygrophorus or translucent appearance is quickly followed by shrinkage of the tissues and weakness of the stem. The plants topple over, the fungus invades all parts, and spreads rapidly to the neighboring individuals. The cells of the sap-perfusecl tissues are flaccid and injured, some showing this even before the entrance of the hyphae into the cells. Somewhat older plants and the more robust seed- lings of cotton, bean, etc., often exhibit characteristic lesions. Atkinson ('95) gives a description of its effect on cotton seedlings as follows: "The trouble is caused by the fungus growing first in the superficial tissues of the stem near the ground and disintegrat- ing them before it passes to the deeper tissues; in other words the fungus never seems to penetrate far in the living tissues, but 'kills as it goes/ and the tissues become brown, depressed, and present the appearance of the plant having a deep and ugly ulcer at the surface of the ground. The fungus does not spread into the tissues either above or below the ulcer to any extent, but literally eats away at that point until it has severed the stem at the affected place or the plant has recovered from its effects." DISEASES OF POTATOES The potato is the most interesting of the host plants with respect to the parasitism of Rhizoctonia by reason of the many types of disease induced under diverse conditions. The conditions may be in part climatic and, in part perhaps, de- pendent upon the pathogenicity of the particular strain of the fungus or upon the stage and development of the host at the time of infection. It has been noted that when Kiihn first de- scribed the disease of potatoes in Germany he laid emphasis up- on a scab which was often followed or accompanied by decay. This form of the disease was probably less prevalent in the country as a whole at that time, and the more recent accounts indicate that the ' ' black speck scab ' ' or " black speck, ' ' prop- erly the sclerotial stage, is the feature by which the main type 434 ANNALS OF THE MISSOURI BOTANICAL GARDEN [V of the disease is now generally known. At present the following main types of injury are recognized for the potato: (1) black speck scab or sclerotial stage, (2) Rhizoctonia scab, (3) Rhizoc- tonia rot, (4) stem lesions and root rot, (5) rosette and leaf roll, and (6) little potato and aerial potato. Black speck is a form of the disease most widely distrib- uted and in itself scarcely merits consideration as a " dis- ease' ' at all, since the sclerotia are superficial on the tuber, and it is merely the appearance of the potato which is affected. The sclerotia may lead to other types of disease which are more serious. The black specks show up most clearly when the potatoes are wet and it is only at this time that they present the appearance of being black, for, as indicated later, the nor- mal color of the sclerotia is deep brown. It was this form of the disease which first gave evidence of the wide distribution of the fungus in America (Duggar and Stewart, '01), and it has been shown to exist in practically all potato-producing sec- tions of the United States and Canada. It occurs throughout Europe, especially on the later varieties of potatoes. It is also reported from India, Africa, and Australia, so that it may be assumed to be world-wide in its distribution on this host. It is safe to say that this is the only form of the disease which does not result directly in serious injury and loss to the crop. In the United States, especially from Ohio westward, other forms of the potato disease assume a seriousness nowhere else attained. If all sucli forms of the disease mentioned below occur in the Atlantic states they are of little consequence. They are, more- over, far less frequent in Europe, India, and Australia. The Rhizoctonia scab is believed to occur as a result of the penetration of hyphae during the early stages of sclerotial development, and occasionally it may be induced by a late growth of new hyphae from old sclerotia. The writer has had an opportunity of examining only casually this form of the dis- ease. It is one of the types doubtless seen by Kiihn. Accord- ing to McAlpine ('11), when this disease occurs, practically every part of the tuber is affected, no normal skin remaining. In severe cases the scab areas may be thrown into folds or puckers and these rub off easily in the form of "cork dust." 1915] DUGGAR RHIZOCTONIA CROCORUM AND R. SOLAN! 435 It is reported that then found at the bases of such scab formations. This scab has been re- ported fairly common in Europe and in Australia. Giissow ('05) seems to refer to the same type in England, and Rolfs ( '03) describes it from Colorado. Specific scabs of the potato have been clearly denned and related to particular organisms. The capacity of the tuber to respond with cork formation to varied injuries suggests that in certain modifications of Rhi- zoctonia scab this fungus may accompany other active scab inducing agents. The Rhizoctonia rot is a form of disease which appears rel- atively late in the season when certain conditions prevail, or possibly when the fungus has for one reason or another de- veloped unusual virulence. The disease is supposed to origi- nate either from stem infections, from sclerotia, or from scab areas. In any case penetration of the mycelium occurs to a considerable depth, and according to McAlpine ('11) there is produced in Tasmania a form of the disease known as brown rust, characterized in the early stages by dark spots in the tuber resembling certain symptoms of Phytophthora. It may also be associated more or less with the deeper form of the Rhizoctonia scab. During the latter part of the season a typi- cal stem rot may occur which is not characterized by the definite lesions described later. Instead, the affected cortex slips readily from the wood and about the bark a considerable web of the yellow-brown hyphae may be found superficially, below and just at the surface of the ground, and the pith may be fairly stuffed with the mycelium. Plants only slightly af- fected with this form of the disease, especially when growing on rich garden or muck soil, have been found to yield the collar or Corticium stage. It is not always easy to distinguish as separate forms of the disease, stem lesions, rosette, little potato, aerial potato, rolling, etc., for these types of injury are often associated. All of these types except stem lesions are properly secondary ef- fects, and there is abundant evidence that all represent responses of the plant to disturbed condition or nutrition, sometimes associated with native weakness. It would not be [Vol. 2 436 ANNALS OF THE MISSOURI BOTANICAL GARDEN strange, therefore, if somewhat similar effects should charac- terize, as they do, purely "physiological" disturbances. Stem lesions are generally dark, sunken areas, clearly different from black leg, occurring at the surface of the ground or on any of the underground stems, or tuber-forming stolons. These lesions may result in the early death of the affected plants. Selby ('02, '03) maintains that generally the lesions upon young shoots are associated with stunted growth and the pro- duction of rosette-like clusters of the upper leaves, as well as with less marked modifications of habit, including slight leaf rolling. Drayton ('15) finds the hyphae in the lesions. If the tuber-bearing stolons are the seat of injury, the food supply is cut off from the young tubers and there may result "little potato," a form of the disease which Rolfs ('04) has found to be an important cause of the potato failures in Colorado. Little potato in Australia is considered an evi- dence of underground injuries occurring late in the season. Injuries which effectually girdle the stem, especially if these occur during a moist season or when the crop is frequently irrigated, lead to the formation of aerial tubers. In the re- lation of Rliizoctonia to the various types of potato diseases much remains to be investigated, and Orton ('14) rightly jsts that inadequate attention has been bestowed upon the question of the predisposition of the tubers used as seed, since it is quite possible that these may yield offspring with tendencies toward resetting, leaf rolling, and other morpho- logical modifications. ?->?-> ROT OF FLESHY ROOTS The root rot of beet, apparently first described by Eidam ('87) in Germany, and shortly afterward found by Pammel ('91) in Iowa, was observed in New York (Duggar, '99) some years later. Since that time it has appeared epidemically in Nebraska (Lvon and AVianco, '02) and other western states. The fungus is most virulent during midsummer or later. In- fection may take place at the bases of the leaves or on the fleshy root. The leaf bases blacken, the leaves become paler, and finally wilt. Pammel ('91) has drawn attention to the 1915] DUGGAR RHIZOCTONIA CROCORUM AND R. SOLANI 437 fact that when fleshy root crops of this type are attacked by such fungi they die gradually, while herbaceous plants (cot- ton, alfalfa, etc.) wilt suddenly. This is probably closely re- lated to the effect of the fungus on the conducting tissues. In the beet root the invaded tissues are pale brown, and often cracks or rifts occur, though rotting may take place without such lesions. Sometimes there is partial recovery after the cracks are formed, and in this case callous tissue is developed. A soft crown rot of the radish induced by this fungus has apparently been reported only once (Duggar and Stewart, '01). A similar disease of the carrot was found in 1900 in New York and this is possibly the disease first reported by Kuhn ('58, pp. 241-243), although he did not identify it as due to a Rhizoctonia. STEM AND HOOT ROTS OF HERBACEOUS PLANTS Rhizoctonia Solani produces serious stem and root rots of a number of economic herbaceous plants, among which the following are known to be important: carnation (Dianthus caryophyllus), Sweet William (Dianthus barbatus), bean (Phaseolus vulgaris), sweet-pea (Lathy rus odoratus), and violet (Viola odorata). The carnation stem rot is one of the most destructive dis- eases occurring on this host and is wide-spread in the United States. The general symptoms of the disease on carnation and Sweet William are much the same. The stem is affected at or just below the soil level. The fungus penetrates and kills the cortex which may be readily slipped from the wood. Through the medullary rays the hyphae also enter the pith, which likewise decays. In later stages of the disease the wood shreds, due to the complete penetration by the fungus of all parenchymatic tissues. Several important epidemics of Rhizoctonia on bean have been reported from different parts of the United States. In addition to the outbreak described by Duggar and Stewart ('01), Hedgcock ('04), a few years later, found the bean dis- ease severe near St. Louis. The base of the stem and the larger roots bore characteristic ulcerations; pods were af- [Vol. 2 438 ANNALS OF THE MISSOURI BOTANICAL GARDEN fected, and through the sunken areas of these the hyphae penetrated the seed and produced small sclerotia on the seed- coats. The fungus was cultivated and typical Rhizoctonia hyphae and sclerotia were obtained. Fulton ('08) observed the disease in Louisiana on stems and pods, with the char- acteristic ulcerations, especially at the surface of the soil or just below. He proved the causal relation of the organism through cultures, and inoculations yielded positive results with the damping off of seedlings. McCready ('10) reported the bean disease as new to Ontario, where it was also char- acterized by stem and pod ulcers. In New York Barrus ('10) observed an epidemic of this host in which as many as 30 per cent of the plants were affected. He determined the fungus by cultural studies and proved its pathogenicity by inoculation. On the sweet-pea the disease is mainly a root rot, yet the base of the stem may also be considerably affected before the plant succumbs. On the violet it is primarily a crown disease, but where the plants are succulent and the con- ditions are moist, the leaves are considerably invaded. FRUIT AND LEAF INJURIES In discussing stem diseases the occurrence of Rhizoctonia on bean pods has been mentioned. Another case of fruit injury is described by Wolf ('14), who found a severe rot of egg plant fruits from which the fungus was obtained. The pathogenicity of the organism was determined by inocula- tions, and cross inoculation from tomato and potato led to the conviction that the organism was Rhizoctonia Solani. Direct attacks of leaves by Rhizoctonia Solani are infre- quent. From the habits of the fungus this would be expected. The one serious leaf disease reported is that of lettuce (Stone and Smith, '00), in which the fungus spreads over the whole surface, causing a moist rot. Sclerotia are frequently formed in connection with this affection. It would be anticipated, perhaps, that diseases of a similar nature might be found on other plants with the rosette habit. Leaf stalks are fre- quently invaded, or may be the regions of first attack, in the case of the beet disease. The disease of leaf stalks of rhubarb 1915] DUGGAR RHIZOCTONIA CROCORUM AND R. SOLANI 439 reported by Duggar and Stewart ('01) is not due to typical R. Solani MYCELIUM AND SCLEROTIA The morphological characteristics of the hyphae and sclerotia have been adequately described by several writers, but it may be well to summarize some of the more important features. Upon such hosts as the potato, sugar beet, carnation, and others there is more or less de- velopment of an external web, but never over the general root system such a complete invest- ment of roots by a mantle of hyphae as characterizes the violet fungus. The external hyphae are somewhat colored, usually yellow- ish brown, and they are generally of two types. One type may be designated as purely vegetative and another as external tufts or masses when these occur. All hyphae are prac- tically colorless when young, vac- uolate, more or less irregular, septate with the septa at intervals of 100-200 1*. The diameter of constituting the 8-12 I* Fig. 5. Jthizoctonia Solani (Cor- ticium vagum) : A vegetative hypha and a small strand from artificial culture on potato. vegetative hyphae is Branches arise, and when young these are inclined in the direction of growth and are invariably somewhat constricted at the point of union with the main hyphae (fig. 5). As the hyphae mature and become more deeply colored they are more uni- form and rigid, the distances between cross walls are greater, the constrictions where branches arise less marked, and the branches are approximately at right angles to the main hypha. On certain affected plants a short tufted or mealy growth occurs and this is made up of hyphae of very different char- acteristics. In the young condition threads are profusely [Vol. 2 440 ANNALS OF THE MISSOURI BOTANICAL GARDEN branched and lobed, sometimes botryoid, and they are ulti- mately divided into short, ovate cells, arranged in short chains, or elbowed, and producing branches in a more or less dichotomous fashion (figs. 7 and 8). In culture the denser Fig. 6. Rhizoctonia Solani : Vegetative hyphae. Fig. 7. Rhizoctonia Solani: a, young hyphae from young sclero- tial tuft on lettuce; b, older cells from same source. masses give rise to sclerotia. With maturity these hyphae be- come light brown in color, they break up readily into short hyphal lengths or single cells, the individuals of which bear some resemblance to conidia. However, they could not easily be mistaken for spores, although they may function as such, inasmuch as most of them may germinate within a few hours when placed under suitable conditions. I have previously de- scribed ('99) this process as follows: "So far as observed, germination is always by the protrusion of a tube through a septum. When several cells are connected, a germ tube from one cell may pass into and through its neighbor, * * * * and thus peculiar appearances may result. Some of the cells of the hyphal chains seem to be devoid of protoplasm, and from neighboring protoplasmic cells the germ 1915] DUGGAR — RHIZOCTONIA CROCORUM AND R. SOLANI 441 tubes seem to pass into such empty cells as readily as directly into the nutrient solution. When the germ tube is from 10 fi to 20 n in length, it is invariably narrowed towards the outlet from the parent cell, and a septum forms at a short distance from this outlet." Fig. 8. Rhizoctonia Solani: Lobulate, moniliform, and elbowed cells from tufted growth in artificial culture. The hyphae which penetrate the tissues remain colorless so long as they are in active growth, and while generally less in diameter they present much the same appearance as the young external hyphae. In the different strains which have been studied, originating from different hosts, certain minor modifications of the general habit of the fungus in culture have been observed. But these have not seemed to be suffi- [Vol. 442 ANNALS OF THE MISSOURI BOTANICAL GA11DEN cient to be considered of specific importance, except in the case of the form on the rhubarb. In general, the differences referred to consist in a variable amount of the mealy or tufted growth, or of the amount of aerial growth; differences in the color of the colony are also observable; and the rapidity with which sclcrotia are formed are all minor distinguishing features. The subject needs further investigation, but in gen- eral it is felt that these differences are such as might be due to permanent differences in the pathological strains, on the one hand, or may be regarded as temporary differences due to the recent environment, on the other. It may be pointed out that the appearance of the mycelium of the beet fungus from the damping off seedlings is not exactly comparable with that of the mycelium derived from the beet rot. When the organisms from both sources are grown in culture they are found to be identical. Strains do occur, however, evidence of which may persist for some time in the general appearance of the cultures. The exact conditions under which sclerotia may occur on the various hosts affected have not been determined. It has been noted that affected potato tubers are the main seats of sclerotia formation when the fungus attacks that host. Upon this plant they are typical, and the numerous illustrations published are sufficient evidence that the appearance is much the same under a variety of conditions. Special attention may be called to the illustrations of Duggar and Stewart ('01), Eolfs ('02), Duggar ('09), McAlpine (11), Pethy- bridge ('11), and Morse and Shapovalow ('11-). On the majority of hosts, however, sclerotial formation is relatively rare. From the various illustrations referred to it will be seen that the sclerotia vary in size from those so minute as to be scarcely visible, to others which may be a centimeter or two in diameter. They are generally more or less flattened, irregular, deep chestnut-brown, and generally smooth on the surface (that is, free from a looser growth of investing hyphae). Smoothness of sclerotia, which has been regarded by Kiihn as of much diagnostic value, should not be considered 1915] DUGGAR RHIZOCTONIA CROCORUM AND R. SOLANI 443 an important character except under natural conditions. Sclerotia which develop on fleshy organs in moist chambers as well as those which develop in culture show to a certain degree, a semi-persistent hyphal investment ; but such invest- ing hyphae are readily worn away, whereas in the violet fungus they are truly persistent. Sections of the denser sclerotia exhibit a fairly homo- geneous structure (fig. 9), with the cells more uniform in size and appearance than in Rhizoctonia Crocorum. Fig. 9. Rhizoctonia Solani: a, from a section of sclerotium on potato; b, cells isolated by maceration of sclerotium. THE BASIDIOSPORE STAGE, SYNONOMY, AND MATERIAL EXAMINED Besides suggestions of a general nature no indications regarding the perfect stage of Rhizoctonia Solani were made prior to the discovery of the Corticium. Prillieux and Dela- croix ('91) described Hypochnus Solani from potato stems, and although at this time the Rhizoctonia diseases were known in Europe no connection with this Hypochnus stage was suspected. The characteristic collar of mycelium was found surrounding the stem just above the surface of the ground, but they found nothing to indicate that the fungus had injured particularly the plant affected. Rolfs ('03) found the collar fungus during his studies of potato diseases in Colorado. The material was determined by Prof. E. A. Burt as referable to the species Corticium vagum B. & C. On account of the parasitic habit, however, [Vol. 2 444 ANNALS OF THE MISSOURI BOTANICAL GARDEN it was considered advisable to make the fungus a variety of the Berkeley and Curtis species, so that it was written Cor- ticium vagum B. & C. var. Solani Burt. Prof. Burt also recog- nized that it agreed closely with, and might be identical with, Ilypochnus Solani Prill. & Del. This conclusion the writer accepts, but in view of the fact that Professor Burt is pre- paring a monograph of the Thelephoraceae, I shall not dis- cuss this point; for the same reason I need only express doubt regarding the validity of Shaw's suggestion that Ilypochnus ochroleucus Noack and Corticium vagum B. & C. are identical, although there is a certain similarity in the various stages. Rolfs ('04) was able to germinate the basidiospores and to develop characteristic Rhizoctonia hyphae from these. Riehm ('11) also reported germinating the basidiospores and producing a characteristic Rhizoctonia mycelium together with the formation of sclerotia. Pethybridge ('15) gives a more complete account of mycelial production from spores. The herbarium and fresh material which has been examined and found to agree with the authentic descriptions of Rhizoc- tonia Solani Kiihn (Corticium vagum B. & C.) may be briefly enumerated : Exsiccati : Rhizoctonia Napaeae nov. sp., Westendorp and Wallays, Herb. Crypt. Fasc. 5: 225. (On decaying turnips which had been stored in a cave.) American material: Hyphal stages on numerous hosts, many of which are mentioned in this paper, also others not included ; sclerotia, on potatoes grown throughout the eastern and central United States, on potato stems (New York, 1900), on bean pods (New York, 1910), also on carnation stems, let- tuce leaves, etc. Corticium stage from Prof. F. H. Rolfs, Colorado, 1901, on potato stems; from Dr. I. C. Jagger, Rochester, New York, 1914, on potato stems and on crown of carrot; from herbarium of Prof. E. A Burt, material on moist soil and decayed wood, collected by Prof. Farlow, Mag- nolia, Mass., 1903; from Herb. Mo. Bot. Garden, Nos. 44679, 44681, and 44682; collected by Dr. Geo. L. Peltier, Urbana, 111., 1915. European material : Sclerotia on potato tubers from Prof. 1915] DUGGAR RHIZOCTONIA CROCORUM AND R. SOLANI 445 Sorauer, Berlin, 1900 ; from Prof. Magnus, Berlin, 1901 ; from Prof. Delacroix, Paris, 1901; and material secured on the markets of various cities, 1905-06. As far as the writer has been able to determine, the fol- lowing synonomy may be listed for Corticium vagum B. & C. : Rhizoctonia Solani Kiihn (1858). Rhizoctonia Betae Eidam [non Kiihn] (1887). Rhizoctonia Napaeae West. (1846). Rhizoctonia Rapae West. (1852). Hypochnus Solani Prill. & Del. (1891). PREVENTION AND CONTROL Much the same situation confronts us regarding the pre- vention and control of Rhizoctonia Solani as in the case of R. Crocorum. The presence of the fungus in practically all soils serves to emphasize the importance of cultural methods including drainage and sanitation. In this case, however, since the fungus is of so much importance in the seed bed and in the greenhouse special preventive measures may be prac- tised. Selby ( '06) found that the treatment of the seed bed with formalin (1:160 to 1:200) proved satisfactory in most cases. In general, the best results have been obtained by steam sterilization, and where the facilities are at hand it is practicable to apply this to any type of greenhouse work, and, in certain cases, to seed beds outside. Liming has been recom- mended for the control of the disease in the field, but this has not been uniformly successful, and cultural studies have shown that the fungus is able to withstand a high percentage of alkalinity. Nevertheless, when liming results in the im- provement of physical and sanitary conditions of the soil it undoubtedly assists in restraining the activity of the fungus in an indirect way, possibly by raising the resistance of the host. Even though the fungus may be widely distributed, it is advantageous to plant clean "seed." This applies particu- larly to the case of the potato. The presence of the sclerotia upon the tuber makes possible the early spread of the fungus 446 ANNALS OF THE MISSOURI BOTANICAL GARDEN [Vol. 2 to the young shoots. It has been positively determined that the more effective tuber treatment is the standard corrosive sublimate solution, as for potato scab. In all cases, however, it would be better to employ seed which are not infected, if this is possible. Conclusions and Notes In the account already given of RMzoctonia Crocorum per- haps sufficient discussion of the occurrence and the character- istics of this form has been entered upon, except in the way of a direct comparison between this species and R. Solani, subsequently included. Further work upon the first named species should consider especially the culture of this organ- ism, inoculation experiments, the development of the organ- ism as it occurs on several hosts, the formation of sclorotia and infection cushions, and the confirmation or more definite declination of Eriksson's view that the fungus is referable to Corticium (Hypochnus). From the study of this organism thus far the following conclusions seem justified: 1. The views of L. and C. Tulasne that the forms of Rhi- zoctonia on crocus, alfalfa, and other hosts may be included in a single morphological species is confirmed. 2. The correct name of the violet root felt fungus, so long as a spore stage remains uncertain, is RMzoctonia Crocorum (Pers.) DC. 3. This organism occurs throughout a considerable part of Europe and has been found in a few localities in America. 4. It attacks a variety of plants representing many fam- ilies, mostly dicotyledonous. 5. The mycelium and sclerotia exhibit no important dif- ferences in equivalent stages on the different hosts, but large sclerotia which form freely in contact with crocus, and often near the affected roots of alfalfa, are seldom observed in con- nection with the attacks upon beets, carrots, and some other hosts. 6. The existence of distinct forms or races of this species reauires further extended studv. 1915] DUGGAR RHIZOCTONIA CROCORUM AND B. SOLANI 447 7. The organism has not yet proved culturable with the usual laboratory methods. 8. At the present time there is insufficient evidence to de- termine what the perfect stage of this organism may be. Obviously much still remains to be done regarding the physiological, pathological, and taxonomic relationship of the culturable forms which in the vegetative stage may be re- ferred to the form-genus Rhizoctonia. The writer has grown in culture Rhizoctonia from twenty-three different American hosts, most of which are mentioned by Duggar and Stewart ('01). Most of these were grown upon a variety of culture media including prune juice, beet, and potato agar ; also beans, stems and pods, celery, sugar beet and potato cylinders, and corn meal mush. With one exception (the organism from rhubarb) the cultural characteristics have been sufficiently similar, especially after protracted culture in the laboratory, to suggest a single species, with characteristics of the beet and cotton fungus, already sufficiently described (Atkinson, '92, '95; Duggar, '99). Moreover, these cultural studies have confirmed in all cases the conclusions tentatively arrived at from the preliminary microscopic examination of the fungus on the different hosts. Eeasons have already been given to indicate why this species is properly R. Solani. It is recog- nized, however, that much culture and inoculation work is necessary to establish the point that the fungus on the various hosts is the same species, and to determine to what extent physiological forms may occur. The following brief summary of conclusions may be pre- sented with regard to Rhizoctonia Solani: 1. The common American species of Rhizoctonia is R. Solani Kiihn. 2. This fungus is widely distributed in America and else- where, and would seem to occur on the potato in most regions of the world where this crop is a staple product. 3. The host plants represent many families of dicot- yledons, Asparagus Sprengeri being the only monocotyle- donous host thus far reported. [Vol. 2 448 ANNALS OF THE MISSOURI BOTANICAL GARDEN 4. The types of disease induced are most diverse, damp- ing off and root and stem rots being the most important direct effects. Secondary effects have been studied only in a few localities. 5. The mycelium and the sclerotia, as well as the general appearance on the host, readily distinguish the fungus from Rhizoctonia Crocorum (Pers.) DC. 6. The organism is readily culturable by the usual labora- tory methods. 7. The evidence seems clear that the perfect stage of this organism is Corticium vagum B. & C. It is to be regretted that the fungus causing a disease of rhubarb (Duggar and SteAvart, '01) was lost before adequate study could be bestowed upon it. The fungus bore a close resemblance to Rhizoctonia, but the aerial hyphal cells were shorter and of greater diameter than those of R. Solani. No sclerotia were found on the host, and they did not develop in culture. Shaw (*13) has contributed interesting notes on diseases of plants in India attributed to two species of Rhizoctonia. Unfortunately, however, he has added to the general con- tusion regarding this subject by a preliminary discussion which does not sufficiently designate the forms referred to, but more especially by the advancement of certain ideas re- srardine: species which are made, apparently, without adequate conclu knowl study of material from other countries. The rived at are necessarily at variance with our _ edge of the forms of Rhizoctonia. Of the organisms producing diseases in Indian crops he refers to Rhizoctonia Solani Kiihn, a fungus which he found on jute, mulberry, cotton, groundnut, and cowpea. The mode of branching of young hyphae of his fungus is characteristic of R. Solani, but with this the resemblance apparently ceases. Basing an opinion wholly upon his descriptions and figures, the adult mycelium (Shaw, '13, pi. 7 and 8) differs from R. Solani (1) in being usually much finer; (2) in the abundant development of short " barrel-shaped" cells in the ordinary 1915] DUGOAR RIIIZOCTONIA CROCORUM AND R. SOLANI 449 vegetative mycelium, which would seem, from his figures, to have little in common with the chain-like, ovoidal, often branched or lobed cells (designated "barrel-shaped" by Balls) of R. Solani (see Atkinson, '92, '95; Balls, '05, '06; Duggar, '99; Duggar and Stewart, '01; and others) ; and (3) in the verrucose or warty, wall markings (Shaw, '13, pi. 8, figs. 2-3), all of which indicate some other fungus. Again, the development of sclerotia (Shaw, '13, pi. 8, fig. 4) discloses a type of hyphal cell not characteristic of R. Solani; and the small discrete sclerotia themselves (Shaw, '13, pi. 2, fig. 3, pi. 8, fig. 1) convincingly indicate that another fungus was under consideration. I can find no record of a description of sclerotia resembling these in the literature of Ehizoctonia diseases. I am at a loss to understand how a fungus with such characteristics could be likened to Killings fungus on the potato, even though depending upon Kiilm's imperfect de- scription. On the other hand, neither in general appearance nor in structure (as described and figured by Shaw) am I able to find any resemblance to the " small sclerotia" or in- fection cushions of R. Crocorum (R. violacea). In moist situations the sclerotia of Rhizoctonia Solani may occur on aerial organs (as on the pods of beans, Hedgcock, '04, on lettuce leaves, Stone and Smith, '00) but the frequent and apparently normal occurrence of minute sclerotia, fairly regularly arranged, on the dead tips of stems, as described by Shaw, finds no parallel in R. Solani. Again, in regard to the hyphae, it may be said that while there is a characteristic location of the septum when a branch is formed in a hypha of Rhizoctonia, this character alone is not sufficient to identify the fungus. It is necessary to take into consideration all of the mycelial characteristics which have been referred to, and if possible also the cultural characters. The writer finds that the "Rhizoctonia type" of branching is more or less similar to that found in the hyphae of certain species of Sclerotinia, Morchella, Pleospora, Rosellinia, and many others. It would be unwise to offer any definite suggestions regarding the fungus described by Shaw and referred to above. What rela- tion it may bear to the fungus of "bangle blight" (Cunning- [Vol. 2 450 ANNALS OF THE MISSOURI BOTANICAL GARDEN ham, '97) must also remain, for the present, uncertain. It is possible that Shaw's fungus is one of the Ascomycetes, at least this is suggested by the figures of the sclerotia. In my opinion Shaw has correctly referred to Corticiuw vagum B. & C. (accordingly to Rhizoctonia Solani Kiihn, representing the vegetative phases of that species) another fungus which he also found in India on the groundnut and cowpea. Both the mycelium and the sclerotia of this second organism as described by him agree with R. Solani as we know it on carnation, beet, bean, lettuce, potato, etc., in America and elsewhere, as far as reported. The descriptions and measurements of basidia and spores are also in sufficient accord. Shaw has even suggested that Rhizoctonia violacea Tul. is the vegetative stage of Corticium vagum B. & C. No such unfortunate confusion could result, however, had he been able to study that which is accepted as Kiihn's organism on the potato together with the violet root felt fungus of Europe on any of its hosts. He has obviously failed to find material of the last named fungus in his studies thus far. Between Rhizoctonia Crocorum and R. Solani in the vege- tative condition some of the important and easily observed contrasting features as usually found are presented in the following table : Rhizoctonia Crocorum Rhizoctonia Solani An external felt, or mantle, of External mycelium, if notice- investing hyphae, confined almost exclusively to under- ground organs. able, only a web, or some- times with flaky tufts, the formation of a "collar" oc- curring only at the time of fruiting. Color of mycelial felt pink-red Color of web, if evident, dirty yellow to yellow-brown. Youn<2; or violet to violet-brown with age. Protoplasm of young hyphal cells soon develops a violet reddish pigment. Infection cushions conspicu- Nothing comparable to infec- hyphal cells hyaline, and even when llavous later, pigment confined to walls. ous in the root-mvestmg mycelium on most hosts. tion cushions, though on potato sclorotia may serve as points of infection. 1915] DUGGAR RHIZOCTONIA CROCORUM AND R. SOLAN! 451 Sclerotia, when present, Sclerotia normally free from densely wooly with invest- any definite or permanent m investment of short, ovoidal or ellip- filaments of elbowed hyphal tical hyphal cells. Internal structure not truly plec- tenchymatic, cells variable in size. Cultures difficult. — not vet cells. homogeneous ii denser sclerotia. structure methods ob- Cultures readily obtained on any nutrient medium. Typically a parasite, with per- Grows rapidly saprophytic- haps the possibility of con- ally on the invaded host, tinuing existence only for a and apparently on debris in aprophytically the soil when conditions are favorable. The following species may be excluded from Rhizoctonia as far as can be judged from reference to the descriptions and to the exsiccati material examined: Rhizoctonia Allii Graves, de Thuemen, Myc. Univ. Fasc. (obviously not closely related to the forms here dis- 6 d) R. bicolor Ell. N. Am. Fung sclerotia like those of a Botrytis, e. g., B Fasc. 10: 977 (with R. Bra Lib., Libert, PI. Crypt. Arduennae, Fasc characteristics of Rhizoct Am. Fung. Fasc. 13 \12( Fasc. 2 : 141. i). R. muscorum Fr. Ellis, N Libert, PI. Crypt. Arduennae From the descriptions alone it would seem that the follow- ing species have insufficient affinities with Rhizoctonia to be included, but critical study of material is needed : Rhizoctonia aurantiaca Ell. & Ev. on decaying wood of Acer; R. Batatas Fr. on Ipomoea Batatas; R. placenta Schw., and R. radiciformis Schw., on decaying wood (the three last mentioned are distributed in Schweinitz', Syn. N. Am. Fung., hich, however, the writer dest T not yet had access) ; R reported parasitic on five species of Del and on Lobelia laxiflora, and H R. moniliformis Ell. & Ev. on branches of Nyssa Rhizoctonia Strobi Scholz ('97) on roots of Pinus strobus in Austria, is insufficiently described to warrant a suggestion ; and R. subepigea Bertoni ( '97) on coffee should be included in a further comparative study. [Vol. 2 452 ANNALS OP THE MISSOURI BOTANICAL GARDEN BIBLIOGRAPHY Atkinson, G. F. ('92). Some diseases of cotton. IV. "Sore-shin," "damping off,' "seedling rot." Ala. Agr. Exp. Sta., Bull. 41 : 30-39. f. 8. 1892. , ('95). Damping off. Cornell Univ. Agr. Exp. Sta., Bull. 94: 301-346 pi. 1-6. f. 55. 1895. [See Damping otf by a sterile fungus, pp. 339-342 f. 55.] , ('02). Studies of some tree-destroying fungi. Mass. Hort. Soc, Trans 1901:109-130. 1902. [See pp. 128-130.] Bailey, F. D. ('15). Rhizoctonia violacea. Ore. Agr. Exp. Sta. Bien. Crop Pest and Hort. Rept. 2:252-255. f. 26. 1915. 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Rapport sur une maladie des asperges dans les environs de Pithiviers. Off. Rens. Agr., Bull. Mens. 1903 : 1108-1113. 1903. [Not seen.] Drayton, F L. ('15). The Rhizoctonia lesions on potato stems. Phytopath. 5 : 59-63. f. 5. pi. 6. 1915. Duby, J. E. ('30). Botanicon Gallicum 2 :p. 867. 1830. Duggar. B. M. ('99). Three important fungous diseases of the sugar beet. Cornell Univ. Agr. Exp. Sta., Bull. 163: 339-363. f. 49-63. 1899. , ('09). Fungous diseases of plants, pp. 444-452. f. 217-222; pp. 477- 479. f. 239. 1909. — », and Stewart, F. C. ('01). A second preliminary report on plant diseases in the United States due to Rhizoctonia. Science, N. S. 13 : 249. 1901. 1 — , ('01). The sterile fungus Rhizoctonia. Cornell Univ. Agr. Exp. Sta., Bull. 186 : 50-76. f. 15-23. 1901. IUd. N. Y. Agr. Exp. Sta., Rept. 19 : 97-121. pi. 8-9. f. 1-7. 1901. Du Hamel du Monceau (1728). Explication physique d'une maladie qui fait pgrir plusieurs plantes, etc. Hist, de l'Acad. roy. d. Sci. d. Paris 1728: 100- 112. pi. 1-2. 1728. Edgerton, C. W. and Moreland, C. C. ('13). Diseases of the tomato in Louisiana. La. Agr. Exp. Sta., Bull. 142: 1-23. f. 1-2. 1913. [See Damping off. p. 22.] Edson, HA. ('15). Seedling diseases of sugar beets and their relation to root- rot and crown-rot. Jour. Agr. Res. 4:135-168. pi 16-26. 1915. [See Rhiz- octonia. pp. 151-159. pi. 16, f. 1; pi. 20-22; pi. 23, f. i.] Eidam, E. ('87). Untersuchungen zweier Krankheitserschceinunger [etc.] Schles. Ges. f. vaterl. Cultur, Jahresb. 65:261-262. 1887. [Abs. in Bot. Cen- tralbl. 35:303-304. 1888.] Ellis, J. B. and Everhardt, B. M. ('84). New species of North American Fungi Torr. Bot. Club, Bull. 11: 17. 1884. Eriksson, J. ('03). Nagra studier ofver morotens rotfiltsjuka, med sarskildt afseende pi dess spridningsformaga. K. Landtbr. Akad. Handl. och Tidskr. 42:309-334. pi. 1. f. 1-J h 1903. , ('03a). Einige Studien iiber den Wurzeltoter (Rhizoctonia violacea) der Mohre, mit besonderer Riicksicht auf seine Verbreitungsfahigkeit. Cen- tralbl. f. Bakt. II. 10:721-738, 766-775. pi. 1. f. 1-$. 1903. [Vol. 2 454 ANNALS OF THE MISSOURI BOTANICAL GARDEN Eriksson, J. (*12) . Svampsjudkomar ii svenska betodlingar. K. Landtbr. Akad, Handl. och Tidskr. 51:410-437. f. 1-9. 1912. [See Rotfiltsjuka. Rhizoctonia violacae Tul. pp. 421-430. f. J f -5.] ('13). Etudes sur la maladie produite par la rhizoctone violacae. Rev. G£n. Bot, 25:14-30. /. i-^. 1913. Fallada, O. ('09, '10). Oesterr.-Ungar. Zeitschr. f. Zuckerind. und Landw. 38 : p. 13. 1909; 39: p. 45. 1910. Frank, A. B. ('96). Die Krankheiten der Pflanzen 2: pp. 514-520. 1896. [2nd ed.] , ('97 ). Ueber die Ursachen der Kartoffelfliule. Centralbl. f. Bakt. II. 3: 13-17, 57-59. 1897. , ('97 a )« Ein neuer Rebenschadiger in Rheinhessen. Zeitschr. f. d. landw. Ver. des Grossh. Hessen 1897 (No. 19): 167-168. [Abs. in Centralbl. f. Bakt. II. 4:781. 1897.] , ('98). Untersuchungen fiber die verschiedenen Erreger der Kartoffel- fiiule. Ber. d. deut. bot. Ges. 16:273-289. 1898. , und Sorauer, P. ('94). Jahresberichte des Sonderaus. f. Pflanzen- schutz 1893-1899. [Arb. d. deut. Landw.- Ges. Heft. 5,8,19,26,29,38,50. Berlin, 1894.] Freeman, E. M. ('08). Diseases of alfalfa. Kan. Agr. Exp. Sta., Bull. 155; pp. 322-328. f. 88-42. 1908. Fries, E. (1823). Systema mycologicum 2: pp. 265-266. 1823. , (1828). Elenehus fungorum 2: pp. 45-46. 1828. Fuckel, L. ('69). Symbolae mycologicae. pp. 142 and 406. Wiesbaden, 1809. Fulton, H. R. ('08). Diseases of pepper and beans. La. Agr. Exp. Sta., Bull. 101: 1-21. f. 1-15. 1908. [See Pod rot and stem rot due to Rhizoctonia, pp. 17-19. f. U-15.] Gandara, G. ('10). Gangrenosis de la raiz de la alfalfa. Mem. y. Rev. Soc. Cient. 29:385-388. f. U,-15. 1910. Gloyer, W. O. ('13). The efficiency of formaldehyde in the treatment of seed potatoes for Rhizoctonia. N. Y. Agr. Exp. Sta., Bull. 370 : 417-431. 1913. Giintz, M. ('99). Beobachtungen iiber den Wurzeltoter von Klee, Rhizoctonia violacea Tul. Fiihlings Landw. Zeit. 48 : 731-732. 1899. [Abs. in Centralbl. f. Bakt. II. 6 : 506-507. 1900.] Giissow, H. T. ('05). Potato scurf and potato scab. Roy. Agr. Soc, Jour. 66: 173-177. f. 8. 1905. , ('06). Beitrag zur Kenntnis der Kartoffel-Grindes. Corticium vagum ^*m -« m ^_*_ ■ - A - « a -_ _ • A _ . _ l a _ _ B. et C. var. Solani Burt. Zeitschr. f. Pilanzenkr. 16 : 135-137. pi. 8. 1906. , ('10). Problems of plant diseases, p. 70. Ottawa, 1910. -, ('12). "Rhizoctonia" disease of potato. Canada Agr. Exp. Farms, Rept. 1912:199-202. f. 3. 1912. , ('14). The storage rots of potatoes. An experiment with Rhizoctonia diseases of potatoes. Canada Agr. Exp. Farms, Rept. 1913:480-485. 1914. Hallier, D. E. (75). Ein gefiihrlicher Feind der Kartoffel. Oesterr. Landw. Wochenbl. 1875:387-388. 1875. [Abs. in Just's Bot. Jahresb. 3:228-229. 1875.] 1915] DUGGAR — RHIZOCTONIA CROCORUM AND R. SOLANI 455 Hartig, R. ('80). Unters. a. d. forstbot. Inst, zu Mtincken 1880 : 1-32. pi. 1-2. 1880. Hartley, C. P. ('12). Damping off by coniferous seedlings. Science, N. S. 36 • 683-684. 1912. ('13). The Bull. 44: 1-21. 1913. U. S. Dept. Agr., Heald, F. D. ('06). Report on the plant diseases prevalent in Nebraska during the season of 1905. Nebr. Agr. Exp. Sta., Rept. 19: p. 40. 1906. ■, ('11 ). Rhizoctonia Medicaginis in America. Phytopath. 1:103. 1911. , and Wolf, F. A. ('00). Tex. Acad. Sci., Trans. 11: pp. 31-32. 1900. , ('11). U. S. Dept. Agr., Bur. PL Ind., Bull. 226 : pp. 39, 40,41,42,43,44,111. 1911. Hedgcock, G. G. ('04). A note on Rhizoctonia. Science, N. S. 19 • 268. 1904. Hibbard, R. P. ('10). Cotton diseases in Mississippi. Miss. Agr. Exp Sta Bull. 140: 1-27. f. 1-8. 1910. [See Damping-off or sore-shin. pp. 17-18. f. *.] Johnson, J. ('14). The control of damping-off disease in plant beds. Wis. Aer Exp. Sta., Res. Bull. 31 : 29-61. 1914. Jones, L. R. ('07). The black leg disease of the potato. Vt. Agr. Exp. Sta., Bull. 129: 101-103. 1907. Kickx, J. ('67). Flore cryptogamique des Flandres 2: p. 470. 1867. Kiihn, J. ('58). Krankheiten der Kulturgewiichse, ihre Ursachen und ihrc VerhUtung. pp. 222-228, 228-239, 243-249. f. 3-22. 1858. Laubert, ('06). Bot. Centralbl. 102:525-527. 1906. L6veill6, J. H. ('43). Memoire sur le genre Sclerotium. Ann. d. Sci. Nat. Bot. 20 : 218-248. pi 6-7. 1843. Lindau, G. ('09). Rabenhorst's Cryptogamen-Flora v. Deutschland, Oesterreich. u. d. Schweisz. 1^:683-686. 1909. Link, H. F. (1824). Hyphomycetes. Linnaeus, Spec. Plant., ed. 4, cur. Willdenow. 61: pp. 119-120. Berlin, 1824. LUstner, G. ('03). Beobachtungen liber den Wurzeltoter der Luzerne (Rhizoctonia, violacea Tul.). K. Lehranst. f. Wein-, Obst-, u. Gartenbau zu Geisenheim a Rh. 1902 : 200-203. f. Jft. 1903. Lyon, T. L. and Wianco, A. T. ('02). Diseases of sugar beets. Nebr. Agr. Exp. Sta., Bull. 73 : 21-23. 1902. Mc Alpine, D. ('11). Rhizoctonia rot, or potato collar fungus. Handbook of fungous diseases of the potato in Australia and their treatment pp. 60-65 pi. 9-13, 19, 39-48. 1911. (cf. pp. 75-77.) McCready, S. B. ('10). Pod and stem rot of beans (Rhizoctonia). Ont. Agr. Coll. and Exp. Farms, Rept. 36 : 46-47. f. 6. 1910. Montagne, C. f50). Etude micrographique de la maladie du safran, connue sous le nom de Tacon. Soc. de Biol., Paris, M6m. 1 [1849] : 63-68. 1850. [Translation by Berkeley, Jour. Hort. Soc. London 5:21-25. 1850.] Morse, W. J. and Shapovalow, M. ('14). The Rhizoctonia disease of potato. Me. Agr. Exp. Sta., Bull. 230 : 193-216. f. 61-73. 1914. Nees von Esenbech, (1816). Das System der Pilze und Schwamme. p. 148. Wurzburg, 1816. [Vol. 2 456 ANNALS OF THE MISSOURI BOTANICAL GARDEN Nelson, A. ('07). Some potato diseases. Wyo. Agr. Exp. Sta., Bull. 71 : 1-39. f. 1-11. 1907. Norton, J. B. S. ('06). Irish potato diseases. Md. Agr. Exp. Sta., Bull. 108 : 63-72. f. l-l 1906. Orton, W. A. ('14). Potato wilt, leaf-roll, and related diseases. U. S. Dept. Agr. Bull. 64: pp. 40-41. pi. 15. 1914. Pammel, L. 11. ('91 ). Fungous diseases of the sugar beet. la. Agr. Exp. Sta., Bull. 15: 234-254. pi 1-7. 1891. [See Preliminary notes on a root-rot disease of sugar beets, pp. 243-251. pi. 3-6.] Peglion, V. ('97). II mal vinato della medica e delle barbietole. Bol. di Entoni. Agron. e Patol. Veg. 4 : 367-369. Padua, 1897. Peltier, G. L. ('14) . Rhizoctonia in America. Phytopath. 4:406. 1914. Persoon, C. H. (1801). Synopsis methodica fungorum. pp. 119-120. 1801. Pethybridge, G. H. ('10). Potato diseases in Ireland. Dept. Agr. and Tech. Instr. for Ireland, Jour. 10:1-18. f. 1-8. 1910. , ('10a). A little known potato disease. Garden 74:560. f. 1. 1910. , ('11). Investigations on potato diseases (second report). Dept. Agr. and Tech. Instr. for Ireland, Jour. 11:29-32. f. 11-14- 1911. ., ('15). "Black speck 11 scab and "collar fungu 1915. Pierson,W. R. ('02). Sterilized soil for stem rot. Gardening 10: 179-181. 1902. Potel, H. C00). Molestias cryptogamicas da batata ingleza e seu tractamento. Bol. da Agr. Estado de Sao Paulo 1 : 45-48. 1900. [See p. 46.] Prillieux, E. ('83). Etude sur deux maladies du safran. Ann. de l'lnst. Nat. Agron. 6: 17-31. pi. S-4. 1883. , ('91). Sur la penetration de la Rhizoctone violette dans les racines de la betterave et de la luzerne. Compt. rend. acad. Paris 113: 1072-1074. 1891. •, ('90). Ibid. Soc. Bot. de France, Bull. 43 : 9-11. f. 1. 1890. ., ('97). Maladies des plantes agricoles 2:144-157. f. 282-287. 1897. , et Delacroix, G. ('91). Hypochnus Solani nov. sp. Soc. Myc. France, Bull. 7:220-221. f. 1. 1891. Prunet, A. ('93). Sur le Rhizoctone de la lucerne. Compt. rend. acad. Paris 117:252-255. 1893. Riehm, E. ('11). Ueber den Zusammenhang zwischen Rhizoctonia Solani Kiihn und Hypochnus Solani Prill, u. Del. K. Biol. Anstalt f. Landw.- u. Forstw., Mitt. 6: p. 23. Berlin, 1911. Rolfs, F. M. ('03). Corticium vagum B. and C. var. Solani Burt. Science, N. S. 18:729. 1903. ('02, '04). Potato failures. Colo. Agr. Exp. Sta., Bull. 70 : 1-20. pi. 1-12. 1902; 91: 1-33. pi. 1-5. 1904. , ('05). (Tomato diseases) Corticium vagum (B. and C). Fla. Agr Exp. Sta., Rept. 1905 : 40-47. 1905. Rostrup, E. ('80). Undersgelser angaaende Svampeslaegten Rhizoctonia. K Dans. Vid. Sels. Forhandl. 1886 : 59-77. pi. 1-2. 1880. 1915] DUGGAR RHIZOCTONIA CROCORUM AND R. SOLANI 457 Koze, E. ('96). Observations sur le rhizoctone de la pomme de terre. Compt. rend. acad. Paris, 123:1017-1019. 1896. — , ( J 97). La maladie de la gale de la pomme de terre et ses rapports avec le Rhizoctonia Solani Kiihn. Soc. Myc. de France, Bull. 13 : 23-28. 1897. Saccardo, P. A. ('99). Syll. Fung. 14: pp. 1175-1177. 1899. Salmon, E. S. ('08). Disease of seakale. Gardeners' Chronicle 44 : 1-3. f. 1-3. 1908. , and Crompton, T. E. ('08). The Rhizoctonia disease of seakale. S. E. Agr. Coll., Wye, Jour. 17:348-353. pi. 21-25. 1908. Scholz, E. R. ('97). Rhizoctonia Strobi, ein neuer Parasit der Weymouthskiefer. K. K. Zool.- Bot. Akad. Ges., Verhandl. 47 : 541-557. f. 1-6. 1897. Selby, A. D. ('02 ). A disease of potato stems in Ohio, due to Rhizoctonia. Science, N. S. 16: 138. 1902. , ('03). A rosette disease of potatoes. Ohio Agr. Exp. Sta., Bull. 139 : 51-66. f. 1-5. 1903. , ('03a, '06). Studies in potato rosette II. Ibid. 145 : 13-28. f. 1-If. 1903. [cf. also, Circ. 57 : 1-7. 1906; and 59 : 1-3. 1906.] , ('04). Tobacco diseases, bed rot. Ibid. 156 : pp. 97-99. pi. 1. 1904, Shaw, F. J. F. ('13). The morphology and parasitism of Rhizoctonia. Dept Agr. India, Mem. 6: 115-153. pi. 1-11. 1913. Sorauer, P. ('86). Pflanzenkrankheiten. pp. 354-361. 1886. (2d ed.) , ('08). Ibid. 2:471-474. 1908. (3d ed., revised by Lindau 1908.) , ^ , - - - — - — — ^ - — j ^ t Stevens, F. L. ('13). The fungi which cause plant disease. Rhizoctonia. pp 406-408. f. 29 3-29 J^ pp. 659-660. 1913. ■ , and Hall, J. G. ('09). Hypochnose of pomaceous fruits. Ann. Myco- logici 7:49-59. f. 1-8. 1909. , and Wilson, G. W. ('11). N. C. Agr. Exp. Sta., Rept. 1911 : 70-73. 1911. Stewart, F. C, French, D. T., and Wilson, J. K. ('08). Troubles of alfalfa in New York. N. Y. Agr. Exp. Sta., Bull. 305 : 330-416. pi. 1-11. 1908. [See Root-rot and damping off. pp. 392-393.] Stift, A. ('00). Der Wurzeltodter oder die Rotfiiule der Riiben (Rhizoctonia violacea Tul.). Die Krankheiten der Zuckerriibe. pp. 67-72. pi. 8-9. Wien, 1900. , ('13). Zur Geschichte des Wurzeltodters oder der Rothfaule (Rhiz- octonia violacea Tul.). Oesterr.-Ungar. Zeitschr. f. Zuckerind. u. Landw. 42 : 445-461. 1913. Stoklasa, J. ('98). Wurzelbrand der Zuckerriibe. Centralbl. f. Bakt. II. 4: 687-694. 1898. Stone, G. E. and Smith, R. E. ('00). The rotting of greenhouse lettuce. Mass. Agr. Exp. Sta., Bull. 69 : 1-40. f. 1-10. 1900. [See A Rhizoctonia disease of lettuce, pp. 16-17. f. 8-10.] ('02). Carnation stem rot. Mass. Agr. Exp. Sta., Rept. 14:67-68. 1902. Tassi, F. ('00). Di una nuova Rhizoctonia. Bui. de Lab. ed Orto Bot. Siena 3 : 49-51. pi. h, f. A-M. 1900. [Vol. 2, 1915] 458 ANNALS OF THE MISSOURI BOTANICAL GARDEN Taubenhaus, J. J. ('14) . The diseases of the sweet pea. Del. Agr. Exp. Sta., Bull. 106: 1-93. f. 1-J f 3. 1914. [See Root rot. pp. 18-27. f. 9-11.] Tubeuf, K. von ('97). [Trans, by W. G. Smith.] Diseases of plants induced by cryptogamic parasites, pp. 201-202. 1897. Tulasne, L. et C. ('62). Fungi Hypogaei. pp. 188-195. pi. 8, f. k\ pi. 9; pi. 20, f. 8-lf. 1862. Van Hook, J. M. ('04). Diseases of ginseng. Cornell Univ. Agr. Exp. Sta., Bull. 219:277-303. f. 18-1/2. 1904. [See Damping off by Rhizoctonia. pp. 289- 291. f. 32-33.] Webber, H. J. ('90). Catalogue of the flora of Nebraska. Nebr. State Bd. Geol., Rept. 1889 : p. 216. 1890. Whetzel, H. H. and Rosenbaum, J. ('12). The diseases of ginseng and their control. U. S. Dept. Agr., Bur. PI. Ind., Bull 250 : 1-44. pi. 1-12. 1912. [See Damping-off of seedlings, pp. 22-23.] Westendorp, G. D. ('52). Notice sur quelques Cryptogames in£dites ou nouvelles pour la llore beige. Acad. Roy. Belg., Bull. 18 2 : p. 402. 1852. Winter, G. Die Pilze. [In Rabenhorst's Cryptogamen-Flora von Deutschland, Oesterreich, u. d. Schweiz l a : p. 277.] Wolf, F. A. ('14). Fruit rots of egg plant. Phytopath. 4:38. 1914. lenweber, H. W. ('13). Pilzparasitare Welkekrankheiten der Ku Ber. d. deut. bot. Ges. 31:17-33. 1913. [See Rhizoctonia. p. 30.] anze SOME RELATIONS OF PLANTS TO DISTILLED WATER AND CERTAIN DILUTE TOXIC SOLUTIONS M. C. MERRILL Formerly Research Assistant to the Missouri Botanical Garden I. Introduction In view of the extensive use of distilled water as a medium in which to grow control plants for comparative purposes in solution-culture work, there is well-grounded justification for the performance of considerable experimental work in order to determine more definitely the relations of plants to this medium. The subject is an important one, and it will require much experimentation for the ultimate solution of all phases of the problem involved. While the results herewith reported are only preliminary in their nature, the fact that they give positive indications along certain lines has been deemed sufficient warrant for their publication at this time. In addi- tion to determining the growth relations of plants in this and other media, consideration has also been given to the effect produced by growing plants in this medium as determined by means of electrical conductivity measurements. II. Historical Aspects of the Subject The relation of plants to distilled water is a matter that has been under more or less serious consideration at differ- ent periods for a long time. Woodward (1699), who first em- ployed the method of water culture in 1691-1692 in his interest- ing experiments, found that plants grew better in river water than in either rain water, spring water, or distilled water. The difference was of course due to the quantity of plant food contained in the medium, and this idea, coupled also with the character of the nutrients, has been the basis for a vast amount of physiological work since that time. Coming down to more modern times, there has been a diversity of opinion among the investigators Ann. Mo. Bot. Gard., Vol. 2, 1915 of the subject (459) [Vol. 2 460 ANNALS OF THE MISSOURI BOTANICAL GARDEN regard to the reason why plants and animals thrive so much better media than in dis tilled water. Considering the period from about 1860 on down to the present, the most important explanations offered may be summed up under the following three heads : 1. Lack of essential nutrients; 2. 3. sub organism immersed in the distilled water. Holding each of these views there has been a formidable array of scientists at different periods, each group contend- ing strongly to establish the correctness of its viewpoint. Among the earlier workers in the field may be mentioned Boehm (75), Deherain (78), and others, who believed that the lack of essential nutrients in the distilled water was responsible for the resulting poor condition of the organism. Boehm, for example, believed that calcium played a funda- mental role in the metabolism of the plant, and that in its absence certain processes, notably that of starch formation, could not be carried on and that therefore deterioration re- sulted. He also believed that calcium was necessary for the transfer of the reserve materials from the cotyledons to the formative organs. Deherain repeated Boehm 's experiments and confirmed his results. Owing to the fact that even distilled water, which had been unquestioningly regarded as pure, produced effects simulat- ing toxicity, a great deal of attention has been given in the past to the chemical and other properties of water distilled from different kinds of apparatus and under various condi- tions. On the animal side, workers, among whom may be mentioned Kolliker ('56) and Nasse ('69), had early noticed the injurious effects on tissues when the same were placed in distilled water. Nasse, for example, found the deleterious effect of distilled water about equal to that of the following solutions : 2.5 per cent NaCl, 3.3 per cent NaBr, 3.7 per cent NaoSO.i, and 5.0 per cent Nal. Nageli ('93), in his classical work published twelve years after his death, found that very minute amounts of toxic sub- 1915] MERRILL DISTILLED WATER 461 stances, notably copper, in solution produced injurious ef- fects on organisms (Spirogyra), and to this phenomenon he applied the term < ' oligodynamik ' ' action. This line of work was extended to include other substances and other organisms, and claimed the attention at different times of Aschoff ('90), Loew ('91), Locke ('95), Ringer ('97), Copeland and Kahlen- berg ('99), Deherain and Demoussy ('01), Lyon ('04), Bokorny ('05), Hoyt ('13), and others. It is of particular interest to note that Ringer in some of his earlier work ascribed the injury to the extraction from the organism of necessary nutrient materials; but after the publication of Locke's experiments ('95), which Ringer duplicated and con- firmed, the latter concluded that the injury done in the par- ticular case under consideration (Tubifex) was due to dele- terious materials in the distilled water. He says : ' ' Copper in even infinitesimal quantities will disintegrate tubifex whilst water free from copper or other heavy metals and without any salts such as calcium salts can sustain the life of tubifex. ' ' In regard to the third idea pertaining to the effects of dis- tilled water on organisms, early workers, both on the plant and animal side, found that salts were extracted from organisms placed in distilled water, even though their methods for determining the extraction were somewhat crude. Among the early investigators on the animal side may be mentioned Plateau ('83), Ringer and his school ('83, '84, '85, '94, >94 a , '94 b , '97), Loeb ('03), and others. The writer has another paper ready for publication in which is given a historical treat- ment of the subject of excretions from roots and other plant parts, so the discussion of certain phases of the plant work is reserved for that publication. Upon the perfection and the employment of conductivity apparatus by physical chemists, it soon began to be used also by the various workers in the fields of soil, plant, and animal investigations. In this connection distilled water came in for its share of consideration. The determination of the purity of water by ascertaining its electrical conductivity speedily came into vogue, and it should be said that as far as elec- I Vol. 2 462 ANNALS OF THE MISSOURI BOTANICAL GARDEN trolytes are concerned it is a very accurate and excellent method and has deservedly come into more and more general use for this purpose in the fields of chemistry, physics, and biology. Koeppe ('98), for instance, determined the electrical con- ductivity of water obtained from various sources and com- pared his results with those of other workers. He believed that distilled water has a deleterious effect which is partly due to a withdrawal of salts necessary to the organism, and partly to a swelling of the tissues. He was supported in his views by Oldham ('09), while Winckler ('04), Kobert ('05), and others argued in favor of the harmlessness of dis- tilled water, especially in medical practice. Peters ('04) used the electrolytic conductivity method in his work on Stentor and found that there was an exosmosis of electrolytes when the organism was placed in distilled water, and he therefore concluded that the injurious effects noted were due to an extraction of salts. True and Bartlett ('12, '15, '15 a ) considered, for certain salts, not only the excretion but also the absorption of electrolytes under balanced and unbalanced conditions of the medium. In a recent paper in which a historical discussion of the subject is also given, True ('14) concludes that over and above any injurious effects caused by deleterious substances in the distilled water there is still a ''residuum of harmful action due to no known type of impurity." Because this harmful action seems to be most marked in water of least conductivity True believes that the withdrawal of electrolytes from the root tissues best accounts for the deleterious action, but that this withdrawal is "not due to the aggregate differ- ence in osmotic pressure between the cells of the roots and the external medium." He chose lupine seedlings for his work because Frank ('88) had found them very sensitive to distilled water. Schulze ('91), however, after several years of experience with Lupinus luteus, claimed that distilled water produced no toxic effects upon those plants. Both before and after the appearance of the recent con- tribution by True just referred to, I carried on the investi- 1915] MERRILL DISTILLED WATER 463 gations reported in this paper, which, as previously stated, are but preliminary in their nature, but which have given indications leading to the conception of an idea differing somewhat from the majority of those above mentioned re- garding the relation between plants and distilled water. This conception will be briefly mentioned here, while the evidence and a further discussion will be given later; it is that pure distilled water is not harmful or injurious per se, but that because of the static condition forced upon them as a con- sequence of the absence of plant food, the growing cells become disorganized and thus become easy prey to bacterial and fungous action. Excretion of electrolytes does occur but this should be considered merely as a concomitant condition, or resulting effect of the conditions under which the plants are placed, and should not be considered as a cause of degen- eration unless the electrolytes themselves be toxic. III. Methods (Germination, Culture, and Conductivity) Canada field peas (Pisum sativum) and horse beans (Vicia faba), the small variety, were the plants selected, as both were known to be well adapted for growth in solution cultures. Of the various methods of seed sterilization tried out, the one in which the seeds were treated with 1-600 formalin-water for 15 minutes after being soaked for 24 hours in running water gave best satisfaction. For germinating the seeds a modification of the method used by Boussingault ('74), and also by various investigators in the Bureau of Soils, was employed. This consisted in the use of ordinary enameled-ware pans about 12 inches in diameter and 3 inches in height, filled with tap water and covered with 6 X 6-mesh galvanized iron "hardware cloth," on which the previously soaked and sterilized seeds were placed. The seeds were then covered with filter paper or paper towelling which was kept moist throughout the ger- mination process or until the radicles reached the water below. The germination was carried on in the greenhouse. In the [Vol. 2 464 ANNALS OF THE MISSOURI BOTANICAL GARDEN course of four or five days a splendid lot of vigorous, uniform seedlings which have serviceably straight radicles about 2 inches long with no laterals yet formed is obtained by this method; such seedlings are well adapted, both by their char- acter and their accommodation to an aqueous medium, for solution-culture work. At this stage the plumules have grown to about one-half inch in length, and the plants are now ready for transfer to the culture medium, an operation which is easily and quickly done. This method of germination, which is shown in pi. 16 fig. 2, recommends itself both by reason of its simplicity and ease of operation and the certainty of secur- ing excellent results. In the transfer process from the ger- minating pan to the culture medium, the entire seedling was always immersed and carefully rinsed in once-distilled and again in twice-distilled water ; by this means the roots became free of any adhering impurities. As containers for the cultures, ordinary glass tumblers were used, the sides of which were covered with black paper to prevent algal growth and the top covered with perforated paraffin paper. (For a complete description and illustration of the method see the paper by McCool, '13.) Ten plants were grown in most cases in each tumbler ; exceptions to that number will be noted in each case when the series are dis- cussed in detail. Galvanized iron wire supports were used to hold the plants upright when the seedlings had attained suffi- cient size to require them. In all cases doubly distilled water was used, the second dis- tillation being carried out in the laboratory with KMnC>4 added to the once-distilled water to oxidize any organic matter that might be present. Conductivity tests of this water showed it to possess a specific conductivity of 2.064x10" The nutrient solution used was that of Pfeffer, redistilled water being the solvent for the necessary salts. Each tumbler was filled to a convenient level with either the water or the full nutrient solution as the case might be, approximately 250 cc. being required. To replace transpiration loss, doubly dis- tilled water was added as needed. In the early days of conductivity work on solutions, 6 1915] MERRILL DISTILLED WATER 465 measurements could be made only by means of a continuous current. Because of the resulting polarization effects, how- ever, the resistance of the solution increased to such an ex- tent as to introduce serious errors into the results. But thanks to the classical work of Kohlrausch and others, the al- ternating current method was devised and perfected, whereby the determinations became practically independent of polar- ization effects. A vast amount of work has since been done in the realm of physical chemistry on conductivity measure- ments, a review of which, however, is outside the scope of this paper. For a clear and concise discussion of this sub- ject see Jones ('09), Walker (10), or Findlay (10). In addition to the investigations already cited which deal with the practical applications of conductivity work, there might well be mentioned in this connection the work done by investigators in the Bureau of Soils of the U. S. Department of Agriculture: Whitney, Gardner, and Briggs ('97); Whit- ney and Briggs ('97) ; Whitney and Means ('97) ; and Gard- ner ('98). Heald ('02) used the Kohlrausch method for de- termining the conductivity of plant juices in order to get indications regarding the dissolved mineral substances in different parts of the plants under experimentation. Nicolosi- Roncati ('07), Bouyoucos (12), Dixon and Atkins (13, 13 a ) and others have also carried on conductivity determina- tions with different plants and under various conditions. Sjoqvist ('95) was the first to use the conductivity method in enzyme investigations, which he did in his work on the action of pepsin on protein solutions. Similar work was done by Oker-Blom ('02), who also extended the applications of this method. Oker-Blom (12) has recently given an account of his own and previous investigations in the field of bacteriology, wherein the electrical conductivity method was used. Various other investigators have also made use of it, among whom may be mentioned Bayliss ('07). Stiles and Jorgensen (14) give a partial review of some of the historical aspects of this subject as it pertains to plant work. [Vol. 2 466 ANNALS OF THE MISSOURI BOTANICAL GARDEN For the conductivity work herein reported the following apparatus was used: Wheatstone bridge (Central Scientific Co., catalogue number, 2475) ; Resistance box, 11,110 ohms (Central Scientific Co., catalogue number, 2444) ; Induction coil (Eimer and Amend, catalogue number, 4100) ; Dry battery cells (Eimer and Amend, catalogue number, 592) ; Conductivity cell, Freas (Eimer and Amend, catalogue number, 5202); Telephone receiver (Central Scientific Co., catalogue number, 2355) ; Thermometer graduated to 1/10°C; Water tank holding 50 gallons, specially constructed for the purpose, pilot flame underneath ; temperature regulated to 1/10°C; Tiffany laboratory motor with which to operate a stirring apparatus in the tank. In the method employed for the work the procedure given below was consistently followed: the tumblers were always filled to approximately the 250 cc. level with either the solu- tion or redistilled water, depending on the culture. Before taking readings, doubly distilled water was added to bring the water or solution up to the original level, if the transpira- tion loss since the previous reading made the addition neces- sary. This was of course essential in order to keep the con- centration factor under control. Readings in all cases were taken at 25° C. The control of temperature exactly to within 1/10° C. was comparatively easy by the use of the pilot flame underneath and the stirring apparatus in the tank of water. For absolutely accurate and final quantitative determina- tions or ultimate values, as were required, for example, in the case of the standardization measurements for the cell constant with N/50 KC1, or the determination of the specific con- ductivity of the doubly distilled water, the greatest precau- tions possible were taken in regard to the conductivity cell and the concentration of its contents. But in making hun- dreds and even thousands of determinations, most of them as rapidly as accuracy permitted, due to the time factor involved, it was both impossible and unnecessary to dry the cell after each reading, since relative, and not absolute, values were 1915 J MERRILL DISTILLED "WATER 467 desired for the most part. The method employed, therefore, was to remove from the carefully stirred solution in the tumbler a 25 cc. sample with a pipette of the same capacity, the latter having previously been rinsed with the solution. Using exactly the same amount for each determination further reduced any possibility of error due to unequal dilution in the conductivity cell. Between readings the pipette was kept almost entirely immersed in redistilled water in a tall cylinder attached to a stand in the water bath. After carefully pour- ing the sample back into the tumbler, in case further readings were to be taken, the cell was rinsed twice with doubly dis- tilled water and rapidly drained before taking the next read- ing, whether of the same or of a different culture. Any minute amount of doubly distilled water that might be present to dilute the next sample was a constant factor throughout all the readings and was of course inconsequential. In using fresh batteries it was necessary to insert resis- tance coils between the battery and the induction coil in order to reduce the current. For this purpose German silver wire was used. While polarization phenomena may possibly be operative to a certain extent, such would be so small as to be practically negligible, especially in view of the fact that the effects from such a cause would be entirely relative and would therefore not affect the validity of the results. Some of the conductivity results given in this paper are shown in tabular form and others are plotted as curves. In some instances the data are calculated as specific conductivity ; in other cases the conductivity is represented by the value of x on the Wheatstone bridge. To make it clear what x actually represents, when the apparatus is set up as it was for the determinations, the following proportion is given: R : R' : : x : 100 ■x R is the resistance in ohms inserted in the resistance box R' is the resistance in ohms of the solution ; and x is the num ber on the bridge wire (graduated in millimeters from t< 100 centimeters). As the position of x on the bridge varies with R and R', the R for each series of curves or tables wil be given (though in the great majority of cases it was 9,110) [Vol. 2 468 ANNALS OF THE MISSOURI BOTANICAL GARDEN from which R' can then be calculated. Having these values, the specific conductivity can be calculated for any determined cell constant (the value of the cell used being .4088). For a fuller discussion see Findlay ('10). IV. Recovery of Plants after being in Distilled Water for Varying Periods The first question studied pertained to the recovery of plants in full nutrient solution after being kept in doubly dis- tilled water for varying periods. To determine the com- parative condition for optimum recovery, the distilled water and the full nutrient medium were renewed every four days in some cultures and left unrenewed in others, in such a way that for either condition of the medium of each set in a cer- tain period the other medium would be both renewed and unrenewed so as to give all possible methods of combination. Examination of table i will make this clear. Thus, for example, with cultures 11, 12, 13, and 14 of the 10-day period in distilled water the doubly distilled water in Nos. 11 and 12 was unrenewed ; but when these cultures were placed in full nutrient solution this medium was unchanged or unrenewed for No. 11 and was renewed for No. 12. The distilled water in Nos. 13 and 14 was renewed, and the full nutrient solution unrenewed and renewed respectively. In series 1 the small variety of horse beans (Vicia faba) was employed, 8 plants being used to a culture. The condi- tion of the media and duration of growth, the green weight of tops, and the dry weight of tops and roots of series 1 are given in table i. On examining this table it is seen that even after the plants had remained for 20 days in distilled water, they recovered on being placed in the full nutrient solution, while those remaining for 10 days in distilled water produced practically as much growth when later placed in the full nutrient solution as did the plants which were in the latter medium during the entire period. Of course, as would be expected, the cultures wherein the full nutrient solution was renewed every four days gave much better growth than did those in the unrenewed medium, due, 1915] MERRILL DISTILLED WATER 469 no doubt, to an increased amount of available nutrients. But an interesting comparison is manifest in connection with the effect of renewing the distilled water; the greater growth of both tops and roots may be noted in cultures 3 and 4, in which TABLE I (Series 1) EFFECT OF RENEWED VS. UNRENEWED MEDIA ON GROWTH OF HORSE BEANS /"* 1 Length of Dist. H 8 Length of Full nutr. Green Dry wt. Dry wt. Culture period in renewed or period in renewed or wt. of of of no. dist. H 2 unrenewed full nutr. unrenewed tops tops roots days days gms. gms. gms. 1 45 45 45 45 1 Unrenewed Unrenewed Renewed Renewed Unrenewed 2.15 1.75 4.40 4.40 16.30 .777 .666 .887 .870 2.069 .124 2 .096 3 .272 4 .235 5 44 Unrenewed .485 6 1 Unrenewed 44 Renewed 27.00 3.069 .707 7 2 Unrenewed 43 Unrenewed 15.85 1.994 .429 8 2 Unrenewed 43 Renewed 32.51 3.543 .743 9 5 Unrenewed 40 Unrenewed 18.90 2.315 .463 10 5 Unrenewed 40 Renewed 26.25 2.895 .700 11 10 Unrenewed 35 Unrenewed 13.35 1.623 .382 12 10 Unrenewed 35 Renewed 26.35 2.928 .697 13 10 Renewed 35 Unrenewed 14.90 1.887 .463 14 10 Renewed 35 Renewed 22.90 2.376 .548 15 15 Unrenewed 30 Unrenewed 14.00 1.719 .388 16 15 Unrenewed 30 Renewed 18.05 1.880 .457 17 15 Renewed 30 Unrenewed 15.60 1.807 .417 18 15 Renewed 30 Renewed 21.20 2.403 .642 19 20 Unrenewed 25 Unrenewed 12.51 1.447 .300 20 20 Unrenewed 25 Renewed 11.40 1.247 .328 21 20 Renewed 25 Unrenewed 11.40 1.319 .284 22 20 Renewed 25 Renewed 15.50 1.670 .454 23 45 45 45 45 Unrenewed Unrenewed Renewed Renewed 14.60 14.70 27.85 27.05 1.975 2.044 2.925 3.025 .419 24 • ^^ ^» ^ .443 25 .690 26 .764 ^^^» ^^ • W ^-^ *^ the distilled water was renewed every four days throughout the period, as compared with that of cultures 1 and 2, where the distilled water was not renewed, except, of course, for the occasional addition of water to replace the transpiration loss, which, however, was small. Furthermore, in noting the growth of cultures 11-22 inclusive, it is seen that in four of the six cases of comparison between the renewed and unre- newed distilled water, better growth of both tops and roots resulted where the distilled water was renewed. Considering cultures 1-4 and 11-22, inclusive, the total green weight of tops for the unrenewed distilled water as compared with the [Vol. 2 470 ANNALS OK THE MISSOURI IIOTANICAL GARDEN renewed distilled water, and the same conditions for the dry weight of tops and roots, gave the results to be seen in table n. The total weight in all cases is therefore greater in the cul- tures in which the distilled water was renewed. TABLE II (Series 1) EFFECT OF RENEWED VS. UNRENEWED DISTILLED WATER ON GROWTH OF HORSE BEANS (Summarized Results of Part of Table I) Medium Green wt. of tops in grams Dry wt. of tops in grams Dry wt. of roots in grams Water renewed . . . Water unrenewed 110.30 99.56 13.219 12.287 3.315 2.772 These therefore indicate that the so-called injury to plants in distilled water cannot be entirely or even satis- factorily explained on the basis of extraction of solutes from s. If that were the case we should have the and least recovery in those cultures in which periodically renewed the t)lant the distilled water was renewed, the per water effecting in toto a greater exosmosis of the salts than the water which is not renewed. This statement will receive verification under the section on conductivity measurements. It would therefore seem that we must seek other explanations for the phenomena observed when plants are placed in dis- tilled water. This phase of the subject will also be discussed later. The points noted will be clear from an examination of pi. 13 figs. 1 and 2. Plate 13 fig. 1 shows the various stages of recovery after varying periods in the distilled water. The better growth is to be noted of both tops and roots of No. 2, in which the distilled water was renewed, as contrasted with No. 1, in which it was not renewed. It is interesting to ob- serve how plants, even after 20 days in distilled water, will recover in full nutrient solution and then give even better growth than plants in unrenewed full nutrient solution the entire period, and that after 10 days in distilled water, plants will recover in renewed full nutrient solution and equal in 1915] MERRILL DISTILLED WATER 471 the full growth, plants grown the entire period in renewed full nut- rient solution. Plate 13 fig. 2 shows first (Nos. 1 and 2) the contrasted effect of renewing and not renewing the full nutrient solution. The remaining 8 cultures of the plate show the effect of renewing and of not renewing both the distilled water and nutrient solution. In cultures 3-10 the comparison should, of course, be made between the alternating numbers for the distilled water effect (renewed or not renewed), and be- tween successive numbers for the effect of the renewal or the non-renewal of the full nutrient solution. While the culture represented by No. 7 of the plate gave greater growth than did No. 9, that excess was probably due to the individual hardi- hood of two plants. It is seen that a much more uniform and desirable growth was made by the plants of No. 9. An interesting point in connection with the horse beans is that 16 days after setting up the series the tips of those plants still in distilled water were more or less blackened, probably as a result of enzyme (oxydase) action, and many of them were considerably inrolled. Such conditions were entirely absent from the cultures in full nutrient solution at that time. When the affected plants were later placed in full nutrient solution there was a gradual recovery from the blackening of the leaves, and this recovery was greater in the case of those cultures in which the distilled water had been renewed than in those in which it had not been renewed. Twenty days later Nos. 3 and 4 were in very much better condition than Nos. 1 and 2. There was much less blacken- ing, some leaves not being blackened at all. The general height of the plants in Nos. 1 and 2 was 1^-2^ inches ; and in Nos. 3 and 4 it was 2£-4 inches. A very noticeable feature at the end of the experiment was the condition of the medium, that of Nos. 3 and 4 beincr of course clear while that of Nos. 1 and 2 was milky, turbid, and opaque, indicating abundant fungous and bacterial action, a condition further emphasized by the hyphal threads and gelatinous coating on the roots. The roots of the plants in Nos. 3 and 4 were also in much better condition at the end of the experiment than were those [Vol. 2 472 ANNALS OF THE MISSOURI BOTANICAL GARDEN of Nos. 1 and 2, especially as regards length and the amount of lateral root development. The root growth in No. 13 at the end of the experiment was also greater than that in No. 11 ; but in Nos. 12 and 14 it was about equal. The plants of No. 17 also showed greater root growth than did those of No. 15, and this difference was more marked than in the case of the tops. The lateral roots in No. 17 were produced all along the main roots, while in No. 15 they were practically confined to the upper or older portion of the main roots. An- other interesting difference observed was that in No. 17 the main root tips were not permanently injured in the distilled water and when placed in the full nutrient solution they con- tinued growth. This was not the case in No. 15. In general there was not much difference between the roots in Nos. 16 and 18; the plants in No. 18, however, had slightly greater growth of roots and showed less injury and some continua- tion of growth of the tips, whereas those in No. 16 did not. The same condition of the roots above noted for Nos. 15 and 17 held also in Nos. 19 and 21 respectively ; but the difference in favor of the renewal of the distilled water though less marked was nevertheless evident. Likewise, Nos. 18 and 20 were similar to Nos. 16 and 18 respectively. Strong evidence was therefore afforded by the cultures of horse beans that renewing the distilled water has a favorable effect upon the plants. & Series 2 is in every respect a duplicate of series 1 except that Canada field peas (Pisum sativum) were used instead of horse beans (Vicia faba), and that the dry weight of the tops was not determined; furthermore, the length of the ex- perimental period was different. The condition of the media and duration of growth, the green weight of tops, and the dry weight of roots are given in table in, seven plants being grown in each culture. An examination of this table reveals results similar in many cases to those contained in table i; plants recovered even after 20 days in distilled water, but after 10 days in this medium the recovery was not so com- plete as in the case of the horse beans, for the plants so treated did not equal in growth similar ones which had remained in 1 915] MERRILL DISTILLED WATER 473 full nutrient solution the entire period. However, plants which had been in distilled water only 5 days before being transferred to full nutrient solution subsequently equalled in growth other plants which had been in the latter medium from TABLE III (Series 2) EFFECT OF RENEWED VS. UNRENEWED MEDIA ON GROWTH OF PEAS Length of Dist. H 2 Length of Full nutr. Green wt. Dry wt. Culture period in renewed or period in renewed or of of no. dist. H 2 unrenewed full nutr. unrenewed tops roots days days gms. gms. 1 47 47 47 47 1 Unrenewed Unrenewed Renewed Renewed Unrenewed .80 .60 .45 1.30 6.75 .073 2 .076 mm 3 .067 4 .091 -A 5 32 Unrenewed .400 6 1 Unrenewed 32 Renewed 11.05 .500 7 2 Unrenewed 31 Unrenewed 5.50 .401 8 2 Unrenewed 31 Renewed 12.90 .568 9 5 Unrenewed 28 Unrenewed 5.95 .263 10 5 Unrenewed 28 Renewed 12.35 .467 11 10 Unrenewed 23 Unrenewed 5.35 .254 12 10 Unrenewed 23 Renewed 7.90 .321 13 10 Renewed 23 Unrenewed 3.80 .160 14 10 Renewed 23 Renewed 6.07 .202 15 15 Unrenewed 18 Unrenewed 3.30 .144 16 15 Unrenewed 18 Renewed 4.40 .175 17 15 Renewed 18 Unrenewed 4.30 .162 18 15 Renewed 18 Renewed 4.15 .169 19 20 Unrenewed 13 Unrenewed 3.21 .124 20 20 Unrenewed 13 Renewed 2.52 .092 21 20 Renewed 13 Unrenewed 4.05 .139 22 20 Renewed 13 Renewed 4.43 .141 23 33 33 33 33 Unrenewed Unrenewed Renewed Renewed 5.50 6.94 9.60 13.45 .368 24 .420 25 .536 26 .611 the start. The period between 5 and 10 days in distilled water is therefore a critical one, and will be discussed later in other connections. Renewing the full nutrient solution again showed beneficial results, as might be expected. But the renewal of the distilled water did not produce such striking results in some respects as in the case of the horse beans ; in other ways, however, the results were equally or even more striking. Where the plants remained in distilled water for 47 days the growth was better in one case and poorer in the other where the distilled water was renewed than where it was not renewed. The average [Vol.. 2 474 ANNALS OF THE MISSOURI BOTANICAL GARDEN' growth, however, of the two cultures in the renewed medium was better than that of the two in the unrenewed distilled water. In Nos. 11-22, there was better growth of tops and roots TABLE IV (Series 2) EFFECT OF RENEWED VS. UNRENEWED DISTILLED WATER ON GROWTH OF PEAS (Summarized Results of Part of Table III) Medium Green wt. of tops in grams Dry wt. of roots in grams Distilled water renewed . . . Distilled water unrenewed.! 28.55 28.08 1.131 1.259 in four cases where the distilled water was renewed and better growth in four cases where it was not renewed. Considering 1-4 and table tained, from which it is again evident that renewing the dis- tilled water exercises no injurious influence, and the conclu- sion is reinforced that an exosmosis of mineral nutrients is not the fundamental basis of the injury which plants suffer in distilled water. Furthermore, the difference between the renewed and the unrenewed distilled water cultures was very marked if the plants remained for 20 days in distilled water before being changed to the full nutrient solution, the differ- ence being greatly in favor of the cultures in which the medium was renewed. Figures 1 and 2 of pi. 14 illustrate the points above men- tioned. In pi. 14 fig. 2 should be noted the better growth of Nos. 9 and 10 — which were in renewed distilled water for 20 days before transfer to full nutrient solution — as compared with Nos. 7 and 8, which had remained in unrenewed distilled water for the same length of time before transfer. The excess of growth in No. 4 over that in No. 6 is probably to be accounted for on the ground that since those cultures were in distilled water but 10 days neither the renewal nor the unrenewal of the medium exercised much effect. Hence the greater growth of No. 4 represents an individual variation. At the expiration of the experimental period the following conditions prevailed in series 2: while the top growth in 1915] MERRILL DISTILLED WATER 475 cultures 1-4 was about the same in each case, the root growth in Nos. 3 and 4 was much better than that in Nos. 1 and 2, the roots of the former being whiter, cleaner, and having longer and more numerous lateral roots. In the case of those cul- tures grown in distilled water 10 days before removal to full nutrient solution, Nos. 11 and 12 were in somewhat better condition than Nos. 13 and 14, a difference which might readily be expected for the shorter periods in distilled water due to individual variation. After 15 days in distilled water and 18 days in full nutrient solution the benefits derived from renewing the former were markedly evident in the appear- ance of cultures 15-18, even though the actual weights did not show such difference. Nos. 17 and 18 were in better condi- tion than Nos. 15 and 16 respectively, especially as regards the root growth; similarly, Nos. 21 and 22 were in better condition than Nos. 19 and 20 respectively. Some special conditions which are of particular interest were observed when the cultures were examined carefully at the close of the experiment. The first point pertains to the method of recovery. After being in the distilled water only one or two days the top growth of such cultures when placed in full nutrient solution proceeds unhindered from the tips of the main stems, i. e., the tips of the stems remain unin- jured and resume growth. But 5 days in distilled water almost marks the limit at which growth can be resumed at the tip of the main axis of the stem when such cultures are subsequently placed in full nutrient solution. After 10 days in distilled water the tips of the stems become injured so that the later growth in full nutrient solution is made from new lateral branches. Hence the period from 5 to 10 days in distilled water before removal to full nutrient solution may be considered a crucial period as regards the recovery and growth of the main stems. Another point of interest is the delayed maturity which results in the case of the cultures which are grown for some time in distilled w T ater and later are placed in full nutrient solution. Such plants remain in a green and growing condi- tion much longer than do those which have been in full [Vol. 2 476 ANNALS OF THE MISSOURI BOTANICAL GARDEN nutrient solution for the entire period, or those which re- mained in distilled water for a shorter period before being transferred to the full nutrient solution. The growing season of the former is thus prolonged and the date of maturity delayed. The foregoing series having given evidence of the recovery of plants in full nutrient solution after being in distilled water for 20 days, the question arose as to the maximum length of time plants might remain in distilled water without preventing recovery when subsequently transferred to full nutrient solution. Series 3 was therefore set up. This con- sisted of cultures of Canada field peas grown in distilled water for 10, 20, 30, 40, and 50-day periods before transfer to the full nutrient medium. The condition of the media and dura- tion in each and also the results of the series (as shown by the green weight of tops) are given in table v, Nos. 1-20 in- clusive. Renewals in this series also were made every four days. Nos. 21-28 under different conditions and concen- tration of nutrient solution are given for purposes of com- parison. The maximum time limit in distilled water above referred to is thus seen to be approximately 30 days, and this was practically attained only in case of the cultures in re- newed distilled water. After 40 days in distilled water, whether renewed or unrenewed, the recovery was almost nil, though somewhat better in the renewed, while after 50 days in either renewed or unrenewed distilled water all the cultures were dead. In the 10 cases furnishing comparisons between cultures in which the full nutrient solution was preceded on the one hand by renewed and on the other by unrenewed distilled water, greater growth was attained in 7 cases where the distilled water was renewed. The total weight of green tops is more nearly equal in the two sets of cultures, however, being 24.20 grams in the case of those in the unrenewed and 22.38 grams in the case of those in the renewed distilled water. We thus see that no injurious effects attend the renewal of the distilled water when compared with the non-renewal of the same; on the other hand, positive benefits are derived from such a 1915] MERRILL DISTILLED WATER 477 renewal, especially in the case of plants approaching the maximum time limit of durability in distilled water — a period which enables the results of the two conditions to be more readily seen and compared. TABLE V (Series 3) GROWTH OF PEAS IN RENEWED AND UNRENEWED MEDIA FOR VARIOUS PERIODS UP TO THE MAXIMUM TIME FOR SURVIVAL. ALSO EFFECT OF ADDING WATER AT DIFFERENT INTERVALS TO MEDIA UNDER VARIOUS CONDITIONS Culture no. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Length of period in dist.H 2 days 10 10 10 10 20 20 20 20 30 30 30 30 40 40 40 40 52 52 52 52 Dist.H 2 renewed or unrenewed Length of period in full nutr. days Unrenewed Unrenewed Renewed Renewed Unrenewed Unrenewed Renewed Renewed Unrenewed Unrenewed Renewed Renewed Unrenewed Unrenewed Renewed Renewed Unrenewed Unrenewed Renewed Renewed 42 42 42 42 32 32 32 32 22 22 22 22 12 12 12 12 Full nutr. renewed or unrenewed Unrenewed full nutr. 42 days, dist. H 8 added every 8 days Unrenewed full nutr. 42 days, dist. H 2 added every 4 days Renewed full nutr. 42 days, the sol'n. renewed every 8 days Renewed full nutr. 42 days, the sol'n. renewed every 4 days Unrenewed l/10fullnutr. 42 days, dist. H 2 added every 4 d'ys Unrenewed 1/5 full nutr. 42 days, dist. H 2 added every 8 days Renewed 1/10 full nutr. 42 days, sol'n. renewed every 4 days Renewed 1/5 full nutr. 42 days, sol'n. renewed every 8 days Unrenewed Renewed Unrenewed Renewed Unrenewed Renewed Unrenewed Renewed Unrenewed Renewed Unrenewed Renewed Unrenewed Renewed Unrenewed Renewed Green wt. of tops gms. 4.50 8.00 4.85 6.30 2.70 5.05 3.55 1.40 .55 1.30 1.90 1.90 .50 .55 .65 .72 .60 .45 .56 .55 6.40 6.00 8.75 18.50 2.90 2.95 10.10 7.85 In pi. 15 fig. 1 some of the cultures are illustrated, the ones of special interest being Nos. 9-14. The exceptionally small or irregular growth of No. 8 is difficult to account for, because in the renewed full nutrient it should be greater than that of No. 7. Individual resistance is apparent, however. [Vol. 2 478 ANNALS OF THE MISSOURI BOTANICAL GARDEN i-> V. Recovery of Plants after being in Toxic Solutions Having thus ascertained the maximum time plants may remain in distilled water and then recover on being placed in full nutrient solution, we may turn our attention to toxic solutions. If distilled water in itself is toxic then it should be interesting to get quantitative data on its effects as measured by the power of plants so treated to recover. This power should furnish a good index regarding the extent of any injury suffered. By comparing the ultimate time limits for various media after which recovery in full nutrient solu- tion is possible, we are able to get a basis on which to de- termine the relative toxicity of each medium. Almost simul- taneously with series 3, series 4 was set up. The plan of the series and the green weight of tops and dry weight of roots of the plants in series 4 are given in table vi, while pi. 15 fig. 2 shows the actual condition of the plants in some of the media. The results obtained indicate the followin toxicities of the substances used, the time expressed in days having reference to the longest period in the toxic solution after which recovery is possible : Redistilled water 30-40 days N/100 MgCl 2 4-8 da y s N/1000 MgCl 2 about 20 days N/1000 CaCl 2 & N/20 MgCl 2 about 16 days N/12800 H 2 S0 4 about 20 days N/400 KOH about 20 days We thus see that as compared with the toxic solutions men- tioned distilled water, if it be considered as a toxic all, is much less so than either of the others given above. In this connection it is interesting to note that Kahlenberg and True ('96) found that N/12800 H 2 SOi and N/400 KOH were approximately the critical concentrations for Lupinus roots. Hence, the fact that plants can remain much longer in distilled water than in these solutions and still recover would seem to indicate that as regards toxicity distilled water is only very slightly if at all deleterious. But the writer believes that it is entirely incorrect and misleading to speak of distilled water as being toxic. What is illustrated above for distilled water is not toxicitv, therefore, but merely the length of time t> 1915] MERRILL DISTILLED WATER 479 TABLE VI (Series 4) EFFECT ON GROWTH OF PLANTS OF VARIOUS PERIODS IN TOXIC SOLUTIONS Culture no. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 First sol'n. or medium Disc. H,0 Dist. H 2 N/100 MgCl, N/100 MgCl, N/100 MgCl, N/100 MgCl, N/100 MgCl, N/100 MgCl, N/100 MgCl, N/100 MgCl, N/100 MgCl, N/1000 MgCl, N/1000 MgCl, N/1000 MgCl, N/1000 MgCl, N/1000 MgCl, N/1000 MgCl, N/1000 MgCl, N/1000 MgCl, N/lOOOCaCl, and N/20 MgCl, N/1000 CaCl, and N/20 MgCl, N/1000 CaCl, and N/20 MgCl, N/1000 CaCl, and N/20 MgCl, N/1000 CaCl, and N/20 MgCl, N/1000 CaCl, and N/20 MgCl, N/1000 CaCl, and N/20 MgCl, N/1000 CaCl, and N/20 MgCl, N/1000 CaCl, and N/20 MgCl, Full nutr. sol'n Full nutr. sol'n N/12800 H,SC»4 N/ 12 800 N/ 12800 N/12800 N/ 12800 N/ 12800 N/400 KOH N/400 KOH N/400 KOH N/400 KOH N/400 KOH N/400 KOH HjSO* H,SO< H.SO, H 2 SO. H,SO< Length of period in first medium days 32 32 32 32 1 2 4 8 12 16 20 32 32 2 4 8 12 16 20 32 32 1 2 4 8 12 16 20 32 32 32 32 2 8 16 20 32 32 2 8 16 20 First medium renewed or unrenewed Length of period in full nutr. Unrenewed Renewed Unrenewedl Renewed Unrenewed Unrenewed Unrenewed Unrenewed Unrenewed Unrenewed Unrenewed Unrenewed Renewed Unrenewed Unrenewed Unrenewed Unrenewed Unrenewed Unrenewedl Unrenewed Renewed Unrenewed Unrenewed Unrenewed Unrenewed Unrenewed Unrenewed Unrenewed Unrenewed Renewed Unrenewed Renewed Unrenewed Unrenewed Unrenewed Unrenewed Unrenewed Renewed Unrenewed Unrenewed Unrenewed Unrenewed days 24 20 16 12 32 32 30 24 16 12 30 24 16 12 Green wt. of tops gms. 1.15 1.55 .35 .40 10.15 8.40 5.15 .35 .30 .40 .28 1.00 1.00 8.85 9.70 7.20 5.15 2.05 1.05 .75 .85 10.60 9.35 10.35 8.40 Dry wt. of roots gms .116 .130 .012 .016 .428 .372 .132 .018 .020 .016 .012 .085 .038 .385 .384 .305 .192 .121 .093 .092 .099 .409 .388 .384 .294 3.00 .144 1.50 .117 .75 .103 8.95 .411 18.50 .530 1.55 .130 1.25 .124 7.05 .318 7.45 .289 4.40 .236 1.95 .172 1.25 .094 1.50 .108 8.60 .444 6.60 .214 2.55 .092 2.60 .117 [Vol. 2 480 ANNALS OF THE MISSOURI BOTANICAL GARDEN plants can survive in a medium without nutrient materials. That these plants could not survive for that length of time in the other media, however, shows that in those cases a real toxicity enters into consideration. In addition to the actual time limits for recovery just tabu- lated, as well as the method of recovery and delayed maturity mentioned in the preceding section, another interesting point, which was very noticeable in the cultures and which can also be seen in the plates, is the character of growth of the root- lets in the boundary cultures, by which is meant those cultures which have remained in the inimical media nearly as long as their endurance would permit, and whose recovery in full nutrient solution is slower or more difficult than the normal unaffected plants. In the latter case the roots are short and compact and usually extend down only to about one-half the distance to the bottom of the tumbler. In the case of the first mentioned cultures, however, when transferred to full nutrient solution the rootlets develop a long, slender growth easily extending to the bottom of the tumbler. S VI. Effect of Sterilizing the Water During Growth of Plants The foregoing series pointed, therefore, to factors other than extraction or loss of solute from the plant tissue as bein responsible for the deteriorating phenomenon observed when growing plants are placed in distilled water. In the unre- newed water cultures in the previous series a brownish colora- tion developed and the roots appeared, in their gelatinized condition, to be covered by bacterial and fungous growths. Suspecting that these organisms played an important role, it was decided to grow additional cultures to test this point. Four cultures, each containing ten plants of Pisum sativum,. were set up in distilled water: in one the medium was not renewed ; in a second the water was renewed every four days ; and in the remaining two the medium was sterilized every four days by boiling in a return condenser one-half hour. The re- sults are given in table vii (series 5) and the cultures are shown in pi. 16 fig. 1. The full nutrient solution cultures, 1915] MERRILL DISTILLED WATER 481 were grown for purposes of comparison. The duration of growth was 30 days. Whether the beneficial effect of the sterilization was due to the destruction of the bacterial and fungous floras of the TABLE VII (Series 5) EFFECT PRODUCED ON GROWTH OF PLANTS BY STERILIZING THE WATER IN WHICH THEY ARE GROWN Culture no. 1 2 3 4 5 6 Medium Dist. H 2 Dist. H 2 Dist. H 2 Dist. H 2 Full nutr. Full nutr. Condition of medium Unrenewed Renewed Sterilized Sterilized Unrenewed Renewed Green wt. of tops gms. 1.55 1.65 2.40 3.05 10.30 17.65 Dry wt. of roots gms. .141 .150 .225 .233 .342 .507 medium, to a decomposition of any contained toxic substances (thereby rendering them less toxic), or to incidental effects such as aeration of the water by the boiling process, was not definitely determined. Neither was this effect compared with that produced by the addition of various bodies (tannic acid, pyrogallol, calcium carbonate, various hydrates, carbon black, and other substances mentioned by Livingston and his co- workers, '05, '07, Dachnowski, '08, '09, and others). In the last paper of Livingston and his co-workers referred to are given the results of boiling the aqueous extracts from soils containing toxic properties as determined by the growth of plants in the same. The boiling improved the extracts, but this effect was explained by " supposing the process of boiling to remove or change the toxic action of this extract, the toxic materials being perhaps partly volatile with steam. ' ' But since in our sterilization process a return condenser was used the removal of toxic substances by volatilization would not occur. A breaking down of toxic compounds into less toxic constituents may possibly be a condition induced by the boiling, however. It will be recalled that Lyon ('04) found the toxicity of tap water reduced by boiling. While the oxidizing power of roots, due to enzymatic activity, may be an important factor in aiding in the decom- [Vol. 2 482 ANNALS OF THE MISSOURI BOTANICAL GARDEN position of vegetable matter in the soil, as pointed out by Schreiner and Reed ('07) and others, it is not believed that in the case under consideration the oxidizing power of the roots was altered to any appreciable degree by the boiling of the medium. Dachnowski ('12) mentions the effect of oxida- tion upon the toxic substances found in bog water. In the sterilization method by boiling under a return condenser, however, the aeration or oxidation phenomenon would no doubt play only a subsidiary role. The stronger line of evi- dence seems to favor the destruction of injurious bacterial and fungous agencies as the chief factor in the beneficial O v "" *•*© effect of the sterilization. VII. Conductivity Measurements The excellence of the electrical conductivity method for determining any change in the electrolyte content of an aqueous medium naturally led to its adoption for the experi- mental work described below. This phase of the investiga- tion was especially concerned with determinations pertaining to the extraction of electrolytes — including the essential nutrient salts — from the roots of plants in distilled water. The generally beneficial results attendant upon a frequent renewal of the distilled water in which the plants were placed has already been noted, as well as the evidence in favor of the view that conditions other than extraction of essential salts constitute the underlying cause of the deterioration of plants in distilled water. The next point to be determined was the relative amount of the total exosmosis in the renewed distilled water as com- pared with that in the unrenewed. In placing roots in dis- tilled water it is pertinent to this subject to inquire whether all the exosmosis occurs during the first four days. If it does, we should have the same amount of extraction in both the unrenewed water and that renewed every four days. Or is there a renewal of the exosmosis of the electrolytes follow- ing the renewal of the water each time, thereby giving rise to a greater exosmosis than in the cultures in which the water was not renewed? If such a condition obtains and yet in 1915] MERRILL DISTILLED WATER 483 spite of it the renewal of the water shows no baneful effects, or indeed produces beneficial results, then may we well con- clude, and with increasing assurance, that extraction of nutrient salts is in no way responsible for any injury plants undergo in distilled water. The results obtained strongly substantiate that conclusion. A series of cultures (series 6) was set up in which healthy plants of Canada field peas were grown in full nutrient solu- tion for about three weeks and then transferred, after care- fully rinsing the roots, to doubly distilled water. In half of the cultures the distilled water was renewed at certain definite intervals for each culture, while in the other half of the cul- tures the water was not renewed. Conductivity determina- tions were then made of the water under both conditions- renewal and non-renewal— at certain regular intervals, vary- ing for each set of cultures, for several days after the plants had been placed in this medium. By numerous readings it was ascertained that with a resis- tance of 9,110 ohms in the resistance box the average value of x on the Wheatstone bridge for the water in the vessel after being rinsed and before placing the roots therein was approxi- mately 6.0, rarely varying 1 cm. either way. Considering that figure, then, as the basis or the starting point for the exos- mosis, and subtracting it from the different values found for the renewed, and from only the final value obtained for the unrenewed distilled water, we get the figures in the last column of table viii. The plan of the experiment with respect to renewal of the distilled water and the time of readings, the values of the individual readings, and the comparative amounts which represent the total exosmosis of the electrolytes under the various conditions of the experiment are all given in table viii. The numbers given are the values of x on the Wheat- ohms bridge when the resistance inserted in the box was 9 It is thus seen that by far the greater exosmosis was ob- tained in the case of those cultures in which the distilled water was renewed. Another point of interest was the reabsorp- [Vol. 2 484 ANNALS OF THE MISSOURI BOTANICAL GARDEN tion of electrolyt of the medium — i s8 — as seen by the decrease in conductivity a those cultures in which the distilled water was not renewed. The reabsorption of electrolytes has been observed to be a phenomenon characteristic of normal, healthy TABLE VIII (Series 6) COMPARATIVE EXOSMOSIS IN RENEWED AND UNRENEWED DISTILLED WATER Culture no. 1 2 3 4 5 6 Water renewal Conductivity Readings Fre- quency Every day None Every 2 days None Every 4 days None Every day Every day Every 2 days Every 2 days Every 4 days Every 4 days 1st 2nd 3rd 4th 5th 32.9 10.4 36.3 22.8 10.8 9.3 25.0 14.3 12.9 15.0 10.7 12.4 10.0 21.4 9.6 13.6 16.1 8.9 17.8 10.7 11.0 16.1 15.9 19.5 9.7 15.2 6th 7th 9.4 12.5 Dura- tion of treat- ment days Total increase in conduc- tivity 10.2 11.4 7 7 8 8 16 16 49.5 5.4 16.4 5.0 36.1 13.5 peas, when transferred from a full nutrient solution to dis- tilled water, after being in the latter medium one or two days. i In order to obtain some additional information regarding the relations between the conductivity of the medium and the plants grown therein, series 7 containing 50 cultures was set up in full nutrient solution, ten Canada field pea plants to each culture. The nutrient solution was not renewed. At the end of each five-day period 5 of the cultures were taken down, the green weight of tops of the plants in each determined, and the conductivity of the solution measured ; and from these results the average weight of tops and the average conductivity of each set of 5 cultures were obtained was done throughout the entire period of 50 days. This The obtained are given in table ix and plotted fig. 1. In the latter the abscissa day and the ordinate both specific conductivity and green weight of top The values given for conductivity should be multiplied by 10" 5 1915] MERRILL DISTILLED WATER 485 in order to get the specific conductivity values. In the case of the weights the numbers in the margin represent ten times the actual weight in grams, e.g., 40 in the margin = 4.0 grams. From the results it is seen that both the increase in green TABLE IX (Series 7) GROWTH OF PLANTS AND CONDUCTIVITY OF FULL NUTRIENT MEDIUM FOR 50 DAYS Cultures nos. Length of period in full nutrient Av. green wt. of tops in each culture Specific conductivity ' of period * at end A * %• WJ# days grams Minimum Average Maximum 1- 5 5 3.81 93.22 96.25 98.19 6-10 10 8.12 57.47 61.03 66.93 11-15 15 9.47 32.38 34.83 37.59 16-20 20 8.66 24.38 32.68 46.05 21-25 25 8.69 15.73 18.19 21.69 26-30 30 8.00 13.74 20.63 30.28 31-35 35 7.10 10.02 15.98 21.23 36-40 40 6.77 11.16 14.23 16.19 41-45 46 6.09 6.88 11.44 22.51 46-50 50 5.01 13.00 16.97 28.11 * The numbers in the three columns are to be multiplied by 10~ 6 in order to arrive at the specific conductivity values. weight of tops and decrease in conductivity of the medium are most rapid and pronounced during the first 15 days. After that period both the green weight and the conductivity gradu- ally decline, but the latter more slowly than the former. curves of the minimum, average, and maximum While the curves conductivity remain very close together during the first 15 days, they become more divergent after that time. The green- weight curve shows a gradual decline as the age of the plant increases, after a certain period, due to the drying of the tops and consequent loss of water. Different curves would, of course, have been obtained had the nutrient solution been renewed. In table x and fig. 2 are seen the results of series 8, a similar experiment with distilled water, the same units being used as in the previous case. The green weight of tops in- creased during the first 10 days and then gradually declined to the end of the experiment. The conductivity of the water was practically the same on the 10th as it had been on the 5th day. Evidence from other experiments, however, indicates 486 ANNALS OK T1IK MISSOURI BOTANICAL GARDKN [Vol. 2 100 95 90 85 80 75 a. S 70 be 65 1 S60 g, T3 55 £*50 45 40 x 35 30 25 20 15 10 5 j r ji t "T" " " "j"r ■ J [' \ _l IV I 11 1 1\ 1 !_ j* L 1 1 7\ r "T" |\i / ^ j_ 111 / Bl I i\i y \ ii\l / s \i\l ? 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J 1 j i r* 1 "^ I j "* s — ■ ■■ tC 1 i /r 1 1 in* T^ " 1 l^P" wl 1 /\~ I I 1 Irsjfl Jb I 1 I s * wi ^ 1 1 1 ^W 11 ! 1 ^-h/^ M i i till r*«n ^4^ m0 \ s^ | / I I 1 "^""l *J /r" I J i *\ p j 1 1 ^ J( L I I t i\a I i Li i i. m .„.,,,,. J. i II \ i i 1 n 1 5 10 15 20 25 Days 30 35 40 45 Fig. 1. The conductivity and growth curves for the full solution (Pfeffer's) in which plants were grown 50 days, the being unrenewed. (For complete explanation see the text.) 50 nutrient medium 1915] MERRILL DISTILLED AVATER 487 that in the interim the ight have risen and fallen After the 10th day the curve inclined with fluctuations. Here again are seen evidences that the 10-day period for seedlings in the distilled water may properly be considered a crucial one for the plants. After that time the growth declines and the conductivity increases markedly. Suspecting that the question of injury to plants in distilled 03 P. s 30 | 25 £ 20 5b c 15 a 10 o 0Q 5 r T"""T1 1 Ml IT / 1^4, k* 1 i> 1 ^kV 1 r^^k^ l / 1 Tvc^ J I 1/ 1-4 i^- £r 1 I A I \ i 1 r>i_ 1 i 1 t \ nI 1 1 1 i vfs^L_ ~] 1 /■ - Z: ^p^J wci^ i I j* *rTr i y i ^ 1 } 1 1 a rX 1 1 / J |N [j 1 i , 2j . I J ^VdJ 1 jL """□ ! Lf | "j ^wCItI \i I J j( ^^^1 ^^^^ ^^^L t ' I aTI / ! "I J^K f ' 3^ " "j "" N^ fftf t > ^ I | A/\\ - 25 05 £20 o 15 10 5 2 4 6 8 10 Days 12 14 16 18 20 Fig. 3. The conductivity curves for cultures in distilled water 20 days — after growth in full nutrient solution for varying periods of time, as follows: Nos. 9-12, 1 day; Nos. 13-16, 5 days; Nos. 17-20, 10 days; Nos. 21-32, 20 days; Nos. 33-36, 30 days; Nos. 37-40, 40 days. Nos. 5-8 were grown only in distilled water, while Nos. 1-4 were without plants, consisting only of distilled water. [Vol. 2 490 ANNALS OF THE MISSOURI BOTANICAL GARDEN for fig. 2 being run in the fall when the seeds were fresh, and that for fig. 3 in the winter), in the vigor of the seeds, and in the difference in the units used in plotting the curves. It must be said, however, that various factors of the problem of exosmosis from the roots of plants remain as yet unknown. The early drop in the curve of the conductivity of the con- trols (1-4) is an interesting feature which would seem to be explained by an adsorption of the electrolytes on the surface of the chemically clean glass tumblers. At the end of 20 days in distilled water the roots of the plants which had not been in full nutrient at all showed marked deterioration (being badly decomposed and covered with a gelatinous coating), while the roots of those which had previ- ously been in full nutrient solution for some time remained normal in every respect, even after 20 days in distilled water. These results seem plainly to indicate that injury which plants sustain in distilled water is very closely related either to the lack of available nutrients in the medium or of reserve food material in the tissues. A seedling is in an exceedingly plastic state of growth. If no food materials become avail- able the embryonic tissues which are in such an active condi- tion of growth soon become disorganized, possibly suffering partial autolysis and becoming the prey to bacterial and fungous action. We would expect, therefore, that the larger the seeds (and hence also the supply of stored materials), the longer the seedlings could remain in distilled water before deterioration. Comparison of True's results on Lupinus with those here presented on Pisum sativum and Vicia faba seems to fulfill that expectation. We should also expect that the more nutrient materials the plant absorbed, the better it would be able later to withstand any deteriorating influences in the distilled water, and the experiment above noted seems to bear out that idea also. In the light of what has been said we are led to believe that the conductivity curve of Nos. 5-8 is not a pure representa- tion of exosmosis and that the products of bacterial and fungous action and cell decomposition account for at least a part of the conductivity. While the same condition may be 1915] MERRILL DISTILLED WATER 491 true of the other cultures to a certain extent, it no doubt plays a lesser, and real exosmosis a greater, part. In connection with the above experiment it was thought desirable to determine whether a difference in the initial tem- perature of the water into which the roots were placed had any immediate or subsequent effect upon the exosmosis from the roots ; plants which had been grown in full nutrient solu- tion for 20 days were used for this purpose. Four cultures were prepared with distilled water at a temperature of 6.5°C, four at 17.2° C, and four at 35.0° C, and conductivity readings were taken after exactly one-half hour, and then at various intervals for 20 days. No attempt was made to keep the water at the initial temperatures and it therefore gradually returned to the temperature of the room. After one-half hour, when the first readings were taken, the respective temperatures were 8.9°C, 16.6°C, and 27.4°C. The average conductivities of the water of these cultures are plotted for 20 days in fig. 4, the same units being used as in fig. 3. From these results it may be concluded that the initial differences of temperature can not be said to have exercised much, if any, effect. The results would probably have been different had the temperatures remained at the original point during the 20 days. Wachter ('05) has con- sidered the role of the temperature factor in exosmosis. VIII. Discussion and Conclusions It is believed that the evidence furnished is sufficient to support the conclusion that pure distilled water per se is not toxic or injurious to plants, and that various other factors enter in to cause the deterioration noted when plants are placed in that medium. Of course by qualifying the assertion to include pure dis- tilled water only, we have thus eliminated the effect that may be produced by toxic substances in the distilled water, no matter from whence derived. The abundance of work that has been done on the toxicity of various substances to plant tissues would of course lead us to expect injurious effects if such substances were present in any quantity in the distilled [Vol. 2 492 ANNALS OF THE MISSOURI BOTANICAL GARDEN water. With that phase of the question we are therefore not much concerned at present. With a distilled water prepared as indicated, and with a specific conductivity which is approxi- mately 2X10 6 J have a water sufficiently pure for e consideration of other aspects of the question, and i m is directed to these. The evidence presented has inclined us strongly to the 30 to X) 3 25 a) 20 o •H o m P 15 10 2 4 6 8 10 Days 12 14 16 18 20 Fig. 4. The conductivity curves for cultures in distilled water 20 days — after growth in full nutrient solution for 20 days. The initial temperatures of the distilled water into which the roots were placed were as follows : Nos. 21-24, 6.5° C; Nos. 25-28, 17.2°C; Nos. 29-32, 35 °C. that the fundamental basis of the deterioration of plants in distilled water rests upon the food relations of such plants, but that, on the other hand, an exosmosis of food materials or nutrient salts is in no way responsible for the difficulty. It is considered that the question of the food relation plays an important role in the incipiency of the disorder, but that this is quickly followed by factors which have been initiated as a result of the inimical food or nutrient relation. 1915] MERRILL DISTILLED WATER 493 A plant must assuredly have food in order to thrive. The more food it has stored up in its tissues, the longer it can survive in a medium devoid of it. But because of the absence of available food it is believed that the tissues of the plant begin to become disorganized and in that condition fall a ready prey to bacterial and fungous action, which may then set in and play a very important part in the subsequent de- composition of the tissues. While it may seem paradoxical to assert in one clause that absence of food is the fundamental basis of the injury which plants undergo in distilled water, and in the very next to say that exosmosis of nutrient salts plays no role, yet the results obtained have substantiated that idea. Furthermore, it is essential to consider the various other factors attendant upon these two conditions in order to arrive at the proper conclu- sions respecting their operation. Among such factors may be mentioned the decrease in conductivity after a short period coincident with exosmosis from normal tissues, the relation of sterilization to bacterial and fungous action, the recovery of plants under different conditions, and the numerous other questions already considered in the body of the article, all of which lend weight to the conclusions arrived at. IX. Summary A brief historical review is given in this paper of the views held in regard to the cause of injury to plants in distilled water. The methods of work are outlined. The experimental work is given and the results discussed, especially with reference to the conclusions of other workers. A discussion is given of the results obtained in the experi- mental work and the conclusions derived therefrom are stated. Some of the results obtained from the experimental work may be summarized as follows : (a). Eenewing the distilled water of the cultures every 4 days was in general beneficial, as shown by increased growth of both tops and roots. The plants were also able to survive longer in the renewed than in the unrenewed distilled water. [Vou 2 494 ANNALS OF THE MISSOURI BOTANICAL GARDEN and continued growth better after being placed in a full nutrient solution. (b). The period between 5 and 10 days in distilled water is a crucial one for plants; if they remain longer in this medium they are unable to recover normally or completely when subsequently placed in a full nutrient solution. (c). By keeping the plants in distilled water a certain period before transferring to full nutrient solution the ma- turity of the plants is delayed. . The longest period during which plants can be kept in distilled water and later recover on being placed in full nutrient solution was found to be 30-40 days. For certain dilute toxic solutions this period was much less, thus indicat- ing that the so-called toxicity of distilled water is, if it exists at all, very slight. (e). The lateral roots of " boundary cultures' ' were characteristically long and thread-like. (f ). Sterilizing the distilled water by boiling one-half hour every 4 days exercised a beneficial effect upon the growth of plants in that medium as compared with the growth of those in unsterilized distilled water. g). Greater total exosmosis was obtained in the renewed than in the unrenewed distilled water. (h). Normal plants which have been grown for some time in full nutrient medium and then transferred to distilled water exhibit at first greater excretion than absorption of elec- trolytes. After one or two days, however, there is greater absorption than excretion and the conductivity curve declines. This condition may be maintained for a considerable period. ( i ) . The conductivity curve of the full nutrient solution in which plants were grown rapidly fell during the first 15 days or so; then it was more or less horizontal for a period, and finally began to incline after about 50 days. The growth general opposite in character to the conducts curve. (j). The conductivity of the distilled water in one series in which the roots of pea seedlings were placed was practically the same on the 10th as on the 5th day. After the 10th day 1915] MERRILL DISTILLED WATER 495 it rose considerably. The growth curve showed a rise the first ten days, then a decline. (k). Higher conductivity in the distilled water after 20 days was caused by plants which had not previously been in full nutrient solution than by plants grown for a time in full nutrient solution before transference to distilled water. The former cultures also failed to give the decline in conductivity characteristic of normal plants transferred from full nutrient solution to distilled water. (1). Greater deterioration of the roots in distilled water occurred if the plants had not previously been in full nutrient solution than in the case of plants which had been grown for a time in the latter medium. (m) . Initial difference of temperature of the distilled water produced no effect on the exosmosis of electrolytes. The sincere thanks of the writer are cheerfully extended the following, who have generously aided in various ways in the preparation of this paper: Dr. B. M. Duggar, for his helpful suggestions and criticisms throughout the work; Dr. J. F. Merrill and Prof. Lindley Pyle, for suggestions in regard to some features of the conductivity apparatus; Mr. C. H. Thompson, for the photographic work ; and Mrs. Amy Lyman Merrill, for assistance in making the calculations, plotting the curves, and in numerous other wavs. Literature Cited Aschoff, C. ('90). Ueber die Bedeutung des Chlors in der Pflanze. Landw. Jahrb. 19: 113-141. pi 2-J h 1890. [See p. 115.] Bayliss, W. M. ('07). Researches on the nature of enzyme-action. I. On the causes of the rise in electrical conductivity under the action of trypsin. Jour Physiol. 36:221-252. 1907. Boehm, J. (75). Uber den vegetabilischen Nahrwerth der Kalksalze. Sitzungs- ber. d. k. Akad. d. Wiss., Wien, math.- naturw. CI. 71 : 287-304. 1875. Bokorny, T. ('05). Das Kupfer und die Giftwirkung des destilliertcn Wassers. Chemiker-Zeit. 29:087-688. 1905. Boussingault, J. (74). Sur la rupture de la pellicule des fruits exposes a une pluie continue. Endosmose des fcuilles ot des racines. Agron., Chim., Agr., et Physiol. 5:303-310. 1874. [See pp. 308-310.] [Vol. 2 496 ANNALS OF THE MISSOURI BOTANICAL GARDEN Bouyoucos, G. ('12). Transpiration of wheat seedlings as affected by different densities of a complete nutrient solution in water, sand, and soil cultures. Beih. z. bot. Centralbl. 29 1 : 1-20. f. S. 1912. [See pp. 14-15.] Copeland, E. B., and Kahlenberg, L. ('99). The influence of the presence of pure metals upon plants. Wis. Acad. Sci., Trans. 12:454-474. 1899. Dachnowski, A. ('08). The toxic property of bog water and bog soil. Bot. Gaz. 46:130-143. f. 1-6. 1908. , ('09). Bog toxins and their effect upon soils. Ibid. 47: 389-405. f. 1-2. 1909. , ('12). Peat deposits of Ohio, their origin, formation, and uses. Ohio Geol. Survey, 4th §er. Bui. 16 : 1-424. pi. 1-8. f. 1-29. 1912. [See pp. 307-342.] Deh6rain, P. P. ('78). Sur l'assimilation des substances min^rales par les plantes. Ann. Agron. 4:321-349. 1878. [See pp. 334-345.] , et Demoussy, E. ('01). Sur la germination dans l'eau distill6e. Compt. rend. acad. Paris 132:523-527. 1901. Dixon, H. H., and Atkins, W. R. G. ('13). Osmotic pressures in plants. -II. Cryoscopic and conductivity measurements on some vegetable saps. Roy. Dublin Soc, Sci. Proc. N. S. 13:434-440. 1913. , , ('13a). Osmotic pressures in plant-organs. III. The osmotic pressure and electrical conductivity of veast, beer, and wort. Ibid. 14 : 9-12. 1913. Findlay, A. ('10). Practical physical chemistry. London, 1910. [See pp. 144-181.] Frank, B. ('88). Untersuchungen iiber die Erniihrung der Pflanze mit Stickstoff und iiber den Kreislauf desselben in der Landwirthschaft. Landw. Jahrb. 17 : 421-553. pi 10-13. 1888. [See p. 535.] Gardner, F. D. ('98). The electrical method of moisture determination in soils: results and modifications in 1897. U. S. Dept. Agr., Div. Soils, Bui. 12 : 1-24. pi. 1-3. f. 1. 1898. Heald, F. D. ('02). The electrical conductivity of plant juices. Bot. Gaz. 34: 81-92. /. 1-2. 1902. Hoyt, W. D. ('13). Some toxic and antitoxic effects in cultures of Spirogyra. Torr. Bot. Club, Bui. 40:333-352. 1913. Jones, H. C. ('09). The elements of physical chemistry. New York, 1909. [See p. 377 ff.] Kahlenberg, L., and True, R. H. ('96). On the toxic action of dissolved salts and their electrolytic dissociation. Bot. Gaz. 22:81-124. 189(3. Robert, R. ('05). Einiges Medizinische iiber das Wasser. Zeitschr. f. Kranken- pfiege 27: 377-384. 1905. Koeppe, H. ('98). Reines Wasser, seine Giftwirkung und sein Vorkommen in der Natur. Deut. med. Wochenschr. 24:G24-62G. 1898. Kolliker, A. ('56). Ueber die Vitalitat der Nervenrohren der Frosche. Wiirz- burger Verhandl. 7: 145-147. 1856. Livingston, B. E., Britton, J. C, and Reid, F. R. ('05). Studies on the prop- erties of an unproductive soil. U. S. Dept. Agr., Bur. Soils, Bui. 28 : 1-39. 1905. 1915] MERRILL DISTILLED WATER 497 , Jensen, C. A., Breazeale, J. F., Pember, F. R., and Skinner, J. J. ('07). Further studies on the properties of unproductive soils. Ibid. 36 : 1-71. pi. 1-7. 1907. Locke, F. S. ('95). On a supposed action of distilled water as such on cer- tain animal organisms. Jour. Physiol. 18:319-331. 1895. Loeb, J. ('03). On the relative toxicity of distilled water, sugar solutions, and solutions of the various constituents of the sea-water for marine ani- mals. Univ. Cal. Publ., Physiol. 1:55-69. 1903. Loew, O. ('91). Bemerkung liber die Giftwirkung des destillirten Wassers. Landw. Jahrb. 20:235. 1891. Lyon, E. P. ('04). A biological examination of distilled water. Marine Biol. Lab., Bui. 6: 198-202. 1904. McCool, M. M. ('13). The action of certain nutrient and non-nutrient bases on plant growth. Cornell Univ. Agr. Exp. Sta., Mem. 2: 113-216. f. 1-15. 1913. von Niigeli, C. ('93). Ueber oligodynamische Erscheinungen in lebenden Zellen. Neue Denkschr. d. allgem. schweiz. Ges. f. gesam. Naturwiss. 33: 1-52. 1893. Nasse, O. ('69). Beitrage zur Physiologie der contraction Substanz. Pfliiger'a Archiv f. gesam. Physiol, d. Menschen u. d. Thiere 2: 97-121. 1 f. 1869. Nicolosi-Roncati, F. ('07). Ricerche su la conduttivita elettrica e la pressione osmotica nei vegetali. Rendic. dell' Accad. Sci. Fis. e Mat. (Sezione della Soc. Reale de Napoli). IIP 13 : 357-364. 1907. Oker-Blom, M. ('02). Die elektrische Leitfiihigkeit und die Gefrierpunktser- niedriguug als lndicatoren der Eiweissspaltung. Skand. Archiv f. Physiol. 13:359-374. 1902. , ('12). Die elektrische Leitfiihigkeit im Dienste der Bakteriologie. Centralbl. f. Bakt. Abt. I. 65:382-389. f. 1-J h 1912. Oldham, R. S. ('09). Is snow-water unwholesome? The Lancet 1909 2 : 1240-1241. 1909. Peters, A. W. ('04). Metabolism and division in Protozoa. Am. Acad., Proc. 39:441-516. 1904. Plateau, F. ('83). Influence de l'eau de mer sur les animaux d'eau douce, et de l'eau douce sur les animaux marins. Compt. rend. acad. Paris 97:467- 469. 1883. Ringer, S. ('83). The influence of saline media on fishes. Jour. Physiol. 4: VI- VIII. 1883. [See section, "Proc. of the Physiol. Soc."] , ('84). Concerning the influence of saline media on fish, etc. Ibid. 5:98-115. 1884. , ('97). The action of distilled water on Tubifex. Ibid. 22:XIV-XV. 1897-1898. , and Buxton, D. W. ('85). Concerning the action of small quantities of calcium, sodium, and potassium salts upon the vitality and function of contractile tissue and the cuticular cells of fishes. Ibid. 6: 154-161. 1885. , and Phear, A. G. ('94a). The influence of saline media on the tadpole. Ibid. 17:423-432. 1894-1895. , , ('94b). The influence of saline media on Tubifex Rivulorum Ibid. 17:XXIII-XXVII. 1894-1895. [See section, "Proc. of the Physiol Soc."] [Vol. 2, 1915] 498 ANNALS OF THE MISSOURI BOTANICAL GARDEN , and Sainsbury, H. ('94) . The action of potassium, sodium, and calcium salts on Tubifex Rivulorum. Ibid. 16: 1-9. 1894. Schreiner, 0., and Reed, H. S. ('07). The r6le of the oxidizing power of roots in soil fertility. Jour. Biol. Chem. 3:XXIV-XXV. 190G-1907. Schulze, E. ('91). Ueber das Verhalten der Lupinenkeimlinge gegen destillirtes Wasser. Landw. Jahrb. 20: p. 230. 1891. Sjoqvist, J. ('95.) Physiologisch-chemische Beobachtungen iiber Salzsiiure. Skand. Archiv f. Physiol. 5:277-376. pi. 7-8. 1895. Stiles, W., and Jorgensen, I. ('14) . The measurement of electrical conductivity as a method of investigation in plant physiology. New Phytol. 13:220-242. f. 1-5. 1914. True, R. H. ('14) . The harmful action of distilled water. Am. Jour. Bot. 1:255-273. f. 1. 1914. , and Bartlett, H. H. ('12). Absorption and excretion of salts by roots, as iniluenced by concentration and composition of culture solutions. I. Concentration relations of dilute solutions of calcium and magnesium nitrates to pea roots. U. S. Dept. Agr., Bur. PI. Ind., Bui. 231: 1-3G. pi. 1 f. 1-21. 1912. 1 1 9 ('15). The exchange of ions between the roots of Lupinus albus and culture solutions containing one nutrient salt. Am. Jour. Bot. 2:255-278. f. 1-13. 1915. , ('15a). The exchange of ions between the roots of Lupinus albus and culture solutions containing two nutrient salts. Ibid. 2:311-323. f. 1-3. 1915. Wiichter, W. ('05). Untersuchungen iiber den Austritt von Zucker aus den Zellen der Speicherorgane von Allium Cepa und Beta vulgaris. Jahrb. f. wisa. Bot. 41: 105-220. 1 f. 1905. Walker, J. ('10). Introduction to physical chemistry. London, 1910. [See p. 237 ff.] Whitney, M., and Briggs, L. J. ('97). An electrical method of determining the temperature of soils. U. S. Dept. Agr., Div. Soils, Bui. 7: 1-15. f. 1. 1897. , Gardner, F. D., and Briggs, L. J. ('97). An electrical method of de- termining the moisture content of arable soils. Ibid. G: 1-20. f. 1-6. 1897. and Means, T. H. ('97). An electrical method of determining the soluble salt content of soils, with some results of investigations on the effect of water and soluble salts on the electrical resistance of soils. Ibid. 8: 1-30. f. 1-6. 1897. Winckler, A. ('04). 1st destilliertes Wasser ein Gift? Zeitschr. diiitet. u. phys. Therapie 8: 567-571. 1904-1905. Woodward, J. (1099). Some thoughts and experiments concerning vegetation. Roy. Soc. London, Phil. Trans. 21: 193-227. 1099. [Vol. 2, 1915] 500 ANNALS OF THE MISSOURI BOTANICAL GARDEN Explanation of Plate Figure Culture no. 1 (2 2 (3 3 (6 4 (8 6 (10 6 (14 7 (18 8 (22 9 (23 10 (25 Figure 1 (9 2 (10 3 (11 4 (12 5 (13 6 (14 7 (19 8 (20 9 (21 10 (22 1. 2. PLATE 13 Conditions of growth. Unrenewed distilled H 2 0, 45 days. Renewed distilled H 2 0, 45 days. 1 day dist. H 2 0, 44 days in renewed full nutr. 2 days dist. H 2 0, 43 days in renewed full nutr. 5 days dist. 11 2 0, 40 days in renewed full nutr. 10 days dist. H 2 (renewed), 35 in renewed full nutr. 15 days dist. H 2 (renewed), 30 in renewed full nutr. 20 days dist. H 2 (renewed), 25 in renewed full nutr. 45 days in unrenewed full nutr. 45 days in renewed full nutr. 5 days in unrenewed dist. H 2 0, 40 days in unrenewed full nutr. 5 days in unrenewed dist. H 2 0, 40 days in renewed full nutr. 10 days in unrenewed dist. 11 2 0, 35 days in unrenewed full nutr. in unrenewed dist. il 2 0, 35 days in renewed full nutr. renewed dist. H 2 0, 35 days in unrenewed full nutr. renewed dist. H 2 0, 35 days in renewed full nutr. unrenewed dist. H 2 0, 25 days in unrenewed full nul unrenewed dist. H 2 0, 25 days in renewed full nutr. renewed dist. H 2 0, 25 days in unrenewed full nutr. renewed dist. H 2 0, 25 days in renewed full nutr. 10 10 10 20 20 20 20 days days days days days days days in in in in in in * The numbers in parentheses correspond to the culture numbers of series 1. (See table 1.) Ann. Mo. Bot. Gakd., Vol. 2, 1915 I'late 13 3 m W K W r t- 1 I U en r 1 -1 > 3 • to COCKAYNE, BOSTON [Vol. 2, 1915] 502 ANNALS OF THE MISSOURI BOTANICAL GARDEN Explanation of Plate Figure 1. Cultu ire no. 1 (2)* 2 (3) 3 (6) 4 (8) 5 (10) 6 (14) 7 (18) 8 (22) 9 (23) 10 (26) Figure 2. 1 (9) 2 (10) 3 (11) 4 (12) 5 (13) 6 (14) 7 (19) : 8 (20) ! 9 (21) ! 10 (22) : PLATE 14 Conditions of growth. 33 days in unrenewed dist. H 2 at time picture w T as taken. 33 days in renewed dist. H 2 at time picture was taken. 1 day in dist. H 2 0, 32 days in renewed full nutr. 2 days in dist. H 2 0, 31 days in renewed full nutr. 5 days in unrenewed dist. H 2 0, 28 days in renewed full nutr. 10 days in renewed dist. H 2 0, 23 days in renewed full nutr. 15 days in renewed dist. H 2 0, 18 days in renewed full nutr. 20 days in renewed dist. H 2 0, 13 days in renewed full nutr. 33 days in unrenewed full nutr. 33 days in renewed full nutr. 5 days in unrenewed dist. H 2 0, 28 days in unrenewed full nutr. 5 days in unrenewed dist. H 2 0, 28 days in renewed full nutr. 10 days in unrenewed dist. H 2 0, 23 days in unrenewed full nutr. 10 days in unrenewed dist. H 2 0, 23 days in renewed full nutr. 10 days in renewed dist. H 2 0, 23 days in unrenewed full nutr. 10 days in renewed dist. IL^O, 23 days in renewed full nutr. 20 days in unrenewed dist. H 2 0, 13 days in unrenewed full nutr. 20 days in unrenewed dist. H 2 0, 13 days in renewed full nutr. 20 days in renewed dist. H 2 0, 13 days in unrenewed full nutr. 20 days in renewed dist. H 2 0, 13 days in renewed full nutr. * The numbers in parentheses correspond to the culture numbers of series 2. (See table in.) Ann. Mo. Bot. Gard.. Vol. 2, 1915 Plate 14 Fig. t Fig. 2 MERRILL— DISTILLED WATER COCKAYNE, BOSTON [V 504 ANNALS Explanation of Plate Figure ] . PLATE 15 Culture no. Conditions of growth. 1 (1)*10 days in unrenewed dist. H 2 0, 42 days in unrenewed full nutr. 2 (2) 10 days in unrenewed dist. II 2 0, 42 days in renewed full nutr. 3 (3) 10 days in renewed dist. H 2 0, 42 days in unrenewed full nutr. 4 (4) 10 days in renewed dist. H 2 0, 42 days in renewed full nutr. 5 (5) 20 days in unrenewed dist. Ii 2 0, 32 days in unrenewed full nutr. tf (G) 20 days in unrenewed dist. H 2 0, 32 days in renewed full nutr. 7 (7) 20 days in renewed dist. H 2 0, 32 days in unrenewed full nutr. 8 (8) 20 days in renewed (list. HoO, 32 days in renewed full nutr. 9 (9) 30 days in unrenewed dist. 11 2 0, 22 days in unrenewed full nutr. 10 (10) 30 days in unrenewed dist. H 2 0, 22 days in renewed full nutr. 11 (11) 30 days in renewed dist. H 2 0, 22 days in unrenewed full nutr. 12 (12) 30 days in renewed dist. H 2 0, 22 days in renewed full nutr. 13 (13) 40 days in unrenewed dist. H 2 0, 12 days in unrenewed full nutr. 14 (15) 40 days in renewed dist. H 2 0, 12 days in unrenewed full nutr. Figure 2. 1 (l)f32 days in unrenewed dist. H2O. 2 (2) 32 days in renewed dist. H 2 0. 3 (20) 32 days in unrenewed N/20 MgCl 2 & N/1000 CaCl 2 . 4 (22) 1 day in unrenewed N/20 MgCl 2 & N/1000 CaCl 2 , 31 days unre- newed full nutr. 5 (23) 2 days in unrenewed N/20 MgCl 2 & N/1000 CaCl 2 , 30 days un- newed full nutr. 6 (24) 4 days in unrenewed N/20 MgCl 2 & N/1000 CaCl 2 , 28 days un- newed full nutr. 7 (25) 8 days in unrenewed N/20 MgCl 2 & N/1000 CaCl 2 , 24 days unre- newed full nutr. 8 (26) 12 days in unrenewed N/20 MgCl 2 & N/1000 CaCl 2 , 20 days un- newed full nutr. 9 (27) 16 days in unrenewed N/20 MgCl 2 & N/1000 CaCl 2 , 16 days unre- newed full nutr. 10 (28) 20 days in unrenewed N/20 MgCl 2 & N/1000 CaCl 2 , 12 days unre- newed full nutr. 11 (29) 32 days in unrenewed full nutrient solution. *The numbers in parentheses correspond to the culture numbers of series 3. (See table v.) fThe numbers in parentheses correspond to the culture numbers of series 4. (See table vi.) Ann. Mo. Bot. Gard., Vol. 2, 1915 Plate 15 p muniiaii yt -\')»M 4ii 1104 m \_*i .,n t*4iv» . , . f ,, 4i A . • , : . _ •jn^h ! t| Fig. 1 Fig. 2 MERRILL— DISTILLED WATER COCKAYNE, BOSTON [Vol. 2, 1915] 506 ANNALS OF THE MISSOURI BOTANICAL GARDEN Explanation of Plate Figure 1. Culture no. PLATE 16 Conditions of growth. 30 days in unrenewed distilled H2O. 30 days in renewed distilled H^O. 30 days in distilled H 2 0, sterilized every four days. 30 days in distilled H 2 0, sterilized every four days. 30 days in unrenewed full nutrient solution. 30 days in renewed full nutrient solution. 1 (D* 2 (2) 3 (3) 4 (4) 5 (5) 6 (6) Figure 2. Showing the method used for seed germination. *The numbers in parentheses also correspond to the culture numbers of ( See table vn. ) series 5. Ann. Mo. Bot. Gard., Vol. 2, 1915 Plate 16 Fig. 1 ■\ Fig. 2 MERRILL— DISTILLED WATER COCKAYNE, BOSTON ELECTEOLYTIC DETERMINATION OF EXOSMOSIS FROM THE ROOTS OF PLANTS SUBJECTED TO THE ACTION OF VARIOUS AGENTS M. C. MERRILL Formerly Research Assistant to the Missouri Botanical Garden I. Introduction In a previous paper the writer ('15) gave some results showing the exosmosis curves when normal growing plants are taken from a full nutrient medium and placed in redis- tilled water. Those results and the data herewith given show that exosmosis of electrolytes is a constant feature associated with the transfer of normal growing plants from a full nutri- ent solution to distilled water. In the paper above mentioned evidence was introduced indicating that such exosmosis was not a causal injury but that it was simply a concomitant con- dition or incidental effect and had but an indirect relation to the inimical condition of the plant in the distilled water. For convenience we might designate the agency or agencies caus- ing such exosmosis as passive in their effects. In this paper are given results on exosmosis in terms of the electrolytic conductivity of the medium when such excretion is caused, or at least is accelerated, by various factors or agen- cies which we may designate as active in their effects. Accord- ingly, plants have been treated by injurious agents or subjected to conditions of different kinds and the comparative effects on the exosmosis from the roots have been noted. By determin- ing the conductivity of the medium at various intervals sub- sequent to the treatment, data have been secured for plotting the exosmosis curves shown in this paper. It has also been the aim to determine in each case the approximate boundary between the normal and the abnormal exosmosis by varying either the duration of application or the concentration of the substance applied, or both. Hence in most cases there will be found the two extremes with any given substance — at the upper end of the scale the curve of excessive exosmosis due to Ann. Mo. Bot. Gard., Vol. 2, 1915 (507) [Vol. 2 508 ANNALS OF THE MISSOURI BOTANICAL GARDEN cytolysis or death of the cells (though it should he noted here that excessive exosmosis from the roots may result even when those tissues are in an apparently normal condition), and at the lower end of the scale the curve of slight exosmosis that is in the region of the normal curve of exosmosis for un- treated plants placed from full nutrient solution into distilled water. Between these two extremes lie various gradations depending on conditions. II. Historical Review The work that has been done on the problem of excretions from the roots of plants is very interesting from several stand- points and has been considered by various workers to be of great practical importance. Nearly a century ago De Candolle ( '32) advocated a theory of crop rotation on the basis of root excretions in which he claimed that certain plants excreted from their roots substances which are harmful to succeeding crops of closely related plants, but not so to plants less closely related. This theory was based partly on his own observations and partly on the statements of earlier workers. At De Candolle 's suggestion Macaire ('32) performed some experimental work pertaining to root excretions. He took plants from the soil, washed the roots carefully, and placed them in rain water. After several days, during which the water was frequently changed, the water was yellow and had odor, taste, and chemical reactions indicative of contained exuded materials. By placing one part of the roots of a plant in a vessel of pure water and another part in a second vessel containing a solution of le