PHYSIOLOGICAL ANIMAL GEOGRAPHY 613 
g. The dominant vegetation of a given area which possesses 
some degree of uniformity of climate (as, for example, the decid- 
uous forest of the United States), is the best index of general 
conditions, as it not only presents the results of the conditions, 
but makes certain types of environmental complex for the animals 
(pp. 582, 601). ' 
h. The field of plant ecology and of ecological plant geography 
present the best data on the distribution of animal environmental 
complexes (p. 601). 
2. The physiology and behavior of animals 
a. In animals, behavior characters take the place of growth- 
form in plants. Animal formations may be characterized by the 
behavior, physiological, and habitudinal relations (mores) of the 
constituent animals, while plant formations are superficially 
characterized by structural characters which indicate the physio- 
logical conditions of the constituent plants (593). 
b. Animal behavior, physiology and general mode of life 
(mores) probably reflect the geographic conditions such as cli- 
mate, general surroundings (vegetation) and other animals present 
(pp. 588, 607). 
c. Physiological animal geography offers a field for experi- 
mentation and observation which will have important bearing 
on human geography, sociology and psychology, and the general 
problems of biology and evolution (p. 609). 
ACKNOWLEDGMENTS 
The author wishes to express his indebtedness to the staff of 
zoology of the University of Chicago, especially to Prof. C. O. 
Whitman for encouraging the study of natural history; to Dr. C. 
M. Child, who suggested our type of experimental study of the 
tiger beetles several years ago: he is indebted also to Dr. H. C. 
Cowles for much advice and information in the field of plant 
ecology; to Dr. Wallace Craig and Prof. H. H. Lane for criticising 
the entire manuscript; to Professor William Ritter and Mr. Ellis 
