PREFACE 



J.HIS small book is pre- 

 sented as a fairly simple statement of a series of 

 interesting facts which belong together although 

 they are not usually treated so. The student of 

 human society has come to regard some of the 

 facts presented in the latter part of the book as 

 fairly within his range of interests. The modern 

 students of scientific natural history who call 

 themselves ecologists for short, are seldom con- 

 cerned beyond the material of the first six chapters. 

 It remains for those of us who are interested in 

 both fields and who find their conjunction when 

 studying the variegated phases of mass physiology 

 to attempt to supply the cement which will hold 

 many of the facts about the life of wild animals 

 in their proper relation with regard to social de- 

 velopment. 



In the preparation of this book, I have purposely 

 omitted citations to technical literature which 

 would give in detail the various facts cited or 

 support the point of view taken. Reference to 

 much of the literature of the subject can be found 

 in recent volumes of the journal, Ecology ; in 

 Allee and Schmidt's American edition of R. 



