x PREFACE TO THE FIRST EDITION 



Because of the almost total lack of herbarium specimens of aquatic 

 Phycomycetes and the paucity of significant data to be derived from 

 such specimens as are available, the would-be monographer of these 

 fungi has, perforce, to seek out his material in nature and to study it 

 in the laboratory in the living state. That a large number of aquatic 

 Phycomycetes have been so studied in preparation for this book has 

 been made possible to a considerable degree by the tenure of National 

 Research Council fellowships in the Biological Sciences and by the 

 hospitality of the directors of many laboratories and institutions. It 

 is a pleasure at this time to express my appreciation to Professor 

 L. M. Massey, chairman, and H. H. Whetzel, acting chairman, of the 

 Department of Plant Pathology, Cornell University; the late Professor 

 Sir Albert Seward, formerly professor of botany, The Botany School, 

 Cambridge University; Professor Knud Jessen, director of the Plante- 

 anatomiske Laboratorium, University of Copenhagen; the director of 

 the Universitetets Havbiologiske Laboratorium, Fredrikshavn, Jutland ; 

 Sir Edwin Butler, F. R. S., sometime director of the Imperial Myco- 

 logical Institute, Kew; John Ramsbottom, F. L. S., Keeper of Botany, 

 the British Museum (N.H.); the late Doctor Reginald Harris, formerly 

 director of the Cold Spring Harbor Biological Laboratory; Professor 

 H. B. Bigelow, lately director of the Woods Hole Oceanographic 

 Institution. I am greatly indebted to my colleagues, Professors H. H. 

 Bartlett, chairman of the Department of Botany, W. R. Taylor, and 

 L. E. Wehmeyer, for advice solicited from time to time. D. H. Linder, 

 S. A. Waksman, H. M. Fitzpatrick, and Ralph Emerson have all 

 contributed in one way or another to the furtherance of this volume. 

 Miss Hilda Harris, librarian of the Farlow Library, Harvard University, 

 and Miss A. C. Atwood, botanical bibliographer of the Bureau of 

 Plant Industry, have been of the greatest assistance in bibliographical 

 matters. 



I am deeply indebted to Professor E. B. Mains, director of the 

 University of Michigan Herbarium, for his painstaking reading of the 

 entire manuscript, for valuable suggestions, and for helpful criticism 

 and advice. Professor J. N. Couch, of the University of North Carolina, 

 kindly read critically the introductory material of the orders and made 

 certain suggestions. 



