PREFACE 



IX 



Chicago Ecology Club, and the resulting 

 discussions were stimulating and profitable. 



We take this opportunity to thank many 

 people for their help in this enterprise. Of 

 course, final responsibifity for all remaining 

 errors rests with the authors. 



Dr. Theodor Just (Chicago Natural His- 

 tory Museum) and the late Dr. Chancey 

 Juday (University of Wisconsin) read all of 

 Section I, and the latter also criticized the 

 material on fimnology in Section IV. The 

 late Dr. F. R. Lilfie, Dr. EHzabeth A. Bee- 

 man (University of Chicago), and Dr. Ruth 

 M. Merwin (National Cancer Institute, 

 Bediesda, Maryland) read Chapter 2, and 

 the last mentioned checked its bibliography. 

 Dr. Garrett J. Hardin (Santa Barbara Col- 

 lege) criticized Chapters 4 to 18, inclusive. 

 Mr. Peter W. Frank and Mr. Gerson Rosen- 

 thal (University of Chicago) each read cer- 

 tain of those chapters. Among others from 

 the same University, Dr. T. F. W. Barth 

 (Geology) checked over the paragraphs on 

 earthquakes. Dr. Ralph W. Gerard (Phys- 

 iology) and Dr. Clay G Huff (Parasitol- 

 ogy) gave similar advice and aid concern- 

 ing other matters in Section H, and Dr. 

 Charles E. Olmsted (Botany) gave help- 

 ful botanical aid. Dr. Fritz Haas (Chicago 

 Natural History Museum) was helpful on 

 various sections. 



Dr. L. C. Birch (University of Sidney) 

 read Chapters 3 and 18 to 22, inclusive. Of 

 the staff of Northwestern University, Dr. 



William Powers aided with Chapter 28, Dr. 

 Orrie J. Eigsti read the material on bacteria, 

 Dr. L. H. Tiffany was consulted with re- 

 spect to photosynthesis, and Dr. Albert 

 Wolfson was helpful on the subject of bird 

 migration (Section IV). 



The following men, all from the Univer- 

 sity of Chicago, helped in the section on 

 Evolution. Dr. Sewall Wright read the 

 whole section. Dr. Herluf H. Strandskov 

 read parts, especially the matters dealing 

 with population genetics. Dr. Clay G Huff 

 and Dr. W. H. Tafiaferro criticized and 

 made suggestions concerning parasitism. Dr. 

 O. H. Robertson helped similarly with the 

 treatment of Fneumococcus, as did Dr. E. 

 J. Kraus with the portion on rusts and with 

 plant ecology, and Dr. John M. Beal with 

 botanical names, evolution of chromosomes, 

 rusts, and at various other places. Dr. Ernst 

 Mayr (American Museum of Natural 

 History) read Chapter 32. Mr. Robert F. 

 Inger was extremely helpful in checking 

 bibUographic references, and our few ref- 

 erences to the Russian literature were put 

 in correct form by Mr. D. D wight Davis 

 (Chicago Natural History Museum). 



The authors are indebted to the Ridge- 

 way Memorial Fund of the University of 

 Chicago for the support that made possible 

 the illustration of the book and to Winifred 

 Emerson for a critical poUshing of the illus- 

 trations. We have freely selected, modified, 

 and redrawn figures from varied somces. 



The Authors 



