vi ANIMAL LIFE 



point of view which the zoological beginner should take 

 is the point of view that the best and most enlightened 

 zoological scholar takes. With this belief in mind the 

 authors have tried to put into simple form the principal 

 facts and approved hypotheses upon which the modern 

 conceptions of animal life are based. 



It is unnecessary to say that this book depends for its 

 best use on a basis of personal observational work by the 

 student in laboratory and field. Without independent 

 personal work of the student little can be learned about 

 animals and their life that will stick. But present-day 

 teachers of biology are too well informed to make a dis- 

 cussion of the methods of their work necessary here. As 

 a matter of fact, the methods of the teacher depend too 

 nearly absolutely on his training and individual initiative 

 to make worth while any attempt by the authors to point 

 out the place of this book in elementary zoological teach- 

 ing. That the phase of study it attempts to represent 

 should have a place in such teaching is, of course, firmly 

 believed by them. 



The obligations of the authors for the use of certain 

 illustrations are acknowledged in proper place. Where no 

 credit is otherwise given, the drawings have been made by 

 Miss Mary H. Wellman or by Mr. James Carter Beard, and 

 the photographs have been made by the authors or under 

 their direction. 



DAVID STARR JORDAN, 

 VERNON LYMAN KELLOGG. 



STANFORD UNIVERSITY, July, 1900. 



