TWENTIETH CENTURY TEXT-B(X)KS. 



TEXT-BOOKS OF ZOOLOGY. 



By David Starr Jordan, President of Leland Stan- 

 ford Jr. University; Vernon Lyman Kellogg, Professor 

 of Entomology; Harold Heath, Assistant Professor of 

 Invertebrate Zoology. 



Evolution and Animal Life. 



This is a popular discussion of the facts, processes, laws, and theories 

 relating to the life and evolution of animals. The reader of it will have 

 a very clear idea of the all-important theory of evolution as it has been 

 developed and as it is held to-day by scientists. 8vo. Cloth, with about 

 300 illustrations, $2.50 net ; postage 20 cents additional. 



Animal Studies. 



A compact but complete treatment of elementary zoology, especially 

 prepared for institutions of learning that prefer to find in a single book 

 an ecological as well as morphological survey of the animal worlH. i2mo. 

 Cloth, $1.25 net. 



Animal Life. 



An elementary account of animal ecology — that is, of the relations 

 of animals to their surroundings. It treats of animals from the stand- 

 point of the observer, and shows why the present conditions and habits 

 of animal life are as we find them. i2mo. Cloth, $1.20 net. 



Animal Forms. 



This book deals in an elementary way with animal morpholc^y. It 

 describes the structure and life processes of animals, from the lowest 

 creations to the highest and most complex. i2mo. Cloth, $1.10 net. 



Animals. 



This consists of " Animal Life " and " Animal Forms " bound in one 

 volume. i2mo. Cloth, f 1.80. 



Animal Structures. 



A laboratory guide in the teaching of elementary zoology. l2mo. 

 Cloth, 50 cents net. 



D. APPLETON AND COMPANY, 



NEW YORK. BOSTON. CHICAGO. LONDON. 



