XVlll ACKNOWLEDGMENTS 



Others who are unfortunately no longer with us, namely the late 

 Professors George E. Nichols of Yale (in ecology) and Merritt L. 

 Fernald of Harvard (in taxonomy). 



Colleagues or friends who have been kind enough to read and 

 give helpful advice about particular chapters or groups of chapters 

 have included Professors G. E. Hutchinson, Harold J. Lutz, Paul 

 B. Sears, and Mr. Albert F. Burke, all of Yale University, Pro- 

 fessors Kenneth V, Thimann and Hugh M. Raup, and Drs. A. F. 

 Hill and Richard E. Schultes, all of Harvard University, Drs. W. O. 

 James, F.R.S., and F. H. Whitehead, both of Oxford University, 

 Drs. H. Hamshaw Thomas, F.R.S., and Harry Godwin, F.R.S., 

 both of Cambridge University, the late Professor Sir Arthur G. 

 Tansley, F.R.S. , of Grantchester, Cambridge, Professor Paul W. 

 Richards of the University College of North Wales, Bangor, Dr. 

 John Hutchinson, F.R.S., of the Royal Botanic Gardens, Kew, Mr. 

 F. T. Walker of the Institute of Seaweed Research, Inveresk, 

 Musselburgh, Scotland, Messrs. Robert Ross and W. T. Stearn, both 

 of the British Museum (Natural History), Dr. Richard S. Cowan of 

 the New York Botanical Garden, Professor G. W. Prescott of 

 Michigan State University, Professor George L. Church of Brown 

 University, Professor Valentine J. Chapman of Auckland University 

 College, New Zealand, Professor G. Einar Du Rietz, of Uppsala, 

 Professors Gunnar Erdtman of Stockholm and Karl H. Rechinger 

 of Vienna (while Visiting Professors in my department at Baghdad, 

 Iraq), Professor Thorvald Sorensen, of Copenhagen, Professor John 

 H. Burnett, now of the University of St. Andrews, Dr. Frank E. 

 Egler of Aton Forest, Norfolk, Conn., and Dr. Edward H. Graham, 

 Director of Plant Technology in the Soil Conservation Service of 

 the United States Department of Agriculture, Washington, D.C. 

 Whereas the choice of these kind mentors was naturally governed 

 largely by their specialist interests, to mention who ' passed ' what 

 might leave them open to being held responsible for errors of com- 

 mission or omission which are in fact my own. Most of the sub- 

 stance of this book was earlier presented in a full-year graduate 

 course at Yale University — a circumstance which, at the instance of 

 some senior participating students, has led to further constructive 

 comment and, surely, improvement. 



In the matter of illustration, so vitally important to a work of 

 this kind, the greatest debt is to Ginn and Company, of Boston, 

 Massachusetts, and Mrs. William H. Brown, for their loan of, and 

 permission to use freely, so many of the fine drawings and photo- 



