FROM PREFACE TO FIRST EDITION 



The present volume is published in response to a demand for a 

 special adaptation of the author's Foundations of Biology, Fourth 

 Edition, designed especially for use in courses in animal biology 

 and general zoology in which plants are considered only inci- 

 dentally in their relations with animals. The essential plan as 

 well as much of the material is, with purpose, the same in both 

 books since the author is apparently far from alone in the convic- 

 tion that the general biological viewpoint affords the natural ap- 

 proach to an introductory survey of either animal or plant science. 



The author continues to be indebted to his colleagues in the 

 Osborn Zoological Laboratory at Yale University and to many 

 others, including his wife, who by suggestions and constructive 

 criticism aided in the development of the book. Special mention 

 is gladly made of the interest expressed by Professor J. W. Bu- 

 chanan of Northwestern University, Professor D. B. Casteel of 

 the University of Texas, Professor W. B. Unger of Dartmouth 

 College, and by Professors W. R. Coe, G. A. Baitsell, J. S. Nicholas, 

 and D. A. Kreider of Yale. 



The author has had again at his disposal the interest and skill 

 of Mr. R. E. Harrison who has drawn a large number of new 

 figures and revised old ones especially for this book. Acknowledg- 

 ments are also due to the authors and publishers of the following 

 works, who have supplied additional illustrations: Chapman's 

 Handbook of Birds of Eastern North America (D. Appleton & 

 Co.) ; Folsom's Entomology (P. Blakiston's Sons & Co.) ; Hough 

 and Sedgwick's The Human Mechanism, Linville and Kelly's 

 General Zoology (Ginn & Co.) ; Martin's Human Body, Sedgwick 

 and Wilson's General Biology (Henry Holt & Co.); Metcalf and 

 Flint's Destructive and Useful Insects, Noble's Biology of the 

 Amphibia (McGraw-Hill Book Co.) ; Romanes' Darwin and After 

 Darwin (Open Court Publishing Co.); Conklin's Heredity and 

 Environment in the Development of Men (Princeton University 

 Press) ; Conn and Budington's Advanced Physiology and Hygiene 

 (Silver, Burdett & Co.); Kudo's Protozoology (C. C. Thomas); 

 Chandler's Animal Parasites and Human Disease, Curtis and 



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