366 VICTOR E. SHELFORD. 



and chemical analysis of soil, water, and air, and be able to 

 experimentally control the factors involved in these. To under- 

 stand technical ecological work, one must be in very close touch 

 with these fields as well as with special ecological matter. The 

 complexity of the problems involved and the lack of training of 

 zoologists along these lines, is sufficient reason for the attitude 

 of an occasional zoologist toward the subject before its problems 

 were clearly formulated. 



IV. SUMMARY. 



1. Ecological or physiological classification of animals is based 

 upon similarities and differences in physiological life histories, 

 reactions to physical factors and the general physiology of environic 

 relations, pp. 339, 354. 



2. There is an agreement between mores of a community due 

 to (a) selection of habitat through innate characters and (&) modi- 

 fication of behavior, p. 336. 



3. The commonly recognized specificities of behavior are of 

 little significance in ecological classification, p. 338. 



4. Adaptation is of questionable significance in ecology ; the most 

 common adaptations are to strata or mode of food getting, p. 340. 



5. Animal communities of greater magnitude are made up of 

 those of lesser magnitude. The physiological agreement in those of 

 greater magnitude is less close than in those of lower, pp. 354-56. 



6. Animal communities are physiologically and genetically 

 (succession) related and their genesis is determined by the 

 genesis of the environment which is usually orthogenetic and 

 converging, p. 359. 



7. The relations of ecology to the phenomena of genetics and of 

 adaptation, are not clear; no relations are apparent but actual 

 relations are experimentally determinable. 



HULL ZOOLOGICAL LABORATORIES. 



UNIVERSITY OF CHICAGO, 



August 25, 1912. 



V. ACKNOWLEDGMENTS AND BIBLIOGRAPHY. 

 The writer is indebted to Dr. H. C. Cowles for the use of his 

 conclusions regarding the Appalachian forests and for assistance 

 with Figs. 5 and 6; he is also indebted to Dr. C. M. Child and 

 Mr. M. M. Wells for reading the manuscript, and to Dr. C. C. 

 Adams for citing Dahl's papers. 



