Preface 



This book has been written for the students, and every effort has been 

 made to produce a volume which can be clearly understood, interesting, and 

 informative. It is intended for a beginning course in zoology on the fresh- 

 man level, but it is also adaptable to beginning courses in biology which may 

 be taught with the concurrent use of a botany text. 



Although the general plan of organization which proved so successful 

 in the first edition has been retained, this edition represents more than a 

 simple revision. New chapters have been included and much new material 

 has been added to chapters carried over from the first edition. In accord- 

 ance with modern zoological developments more space has been allotted to 

 physiology both in the introductory chapters and in the survey of the animal 

 kingdom. The sections on genetics and ecology have been expanded con- 

 siderably in the light of increased emphasis on these subjects in beginning 

 courses. In general the changes have been toward a book with somewhat 

 more rigor, yet one that retains the clear-cut explanations and interest- 

 stimulating references which have proved to make understanding easier. 



Too often the interesting principles of zoology are ensnarled in the maze 

 of technical words that have no more meaning for the beginning student 

 than a foreign language. In order to avoid this pitfall the authors have 

 used easy-to-understand language in the first part of the book and wherever 

 a technical word, not in the vocabulary of the average college freshman, is 

 first used it is explained thoroughly. In this way a vocabulary is gradually 

 developed so that more scientific words can be used in later chapters. 



This edition is marked by the addition of a junior co-author (Lovell) 

 whose work as a critical reader has been valuable, who has rewritten many 

 sections, and who is primarily responsible for Chapter 16 (The Honeybee), 

 Chapter 29 (The Distribution of Animals), Chapter 30 (Ecology and 

 Conservation), and Chapter 33 (The Development of the Individual). 



A. M. Winchester 

 Harvey B. Lovell 



