TWENTIETH CENTURY TEXT-BOOKS. 
TEXT-BOOKS OF ZOOLOGY. 
By Davip Starr Jorpan, President of Leland Stan- 
ford Jr. University; VERNon Lyman KELLOGG, Professor 
of Entomology; Harotp Hearn, 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 world.. 12mo, 
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. 12mo. Cloth, $1.20 net. 
Animal Forms. 
This book deals in an elementary way with animal morphology. It 
describes the structure and life processes of animals, from the lowest 
creations to the highest and most complex. 12mo. Cloth, $1.10 net. 
Animals. 
This consists of “ Animal Life” and “ Animal Forms” bound in one 
volume. I2mo, Cloth, $1.80. 
Animal Structures. 
A laboratory guide in the teaching of elementary zoology. 12mo, 
Cloth, 50 cents net. 
D. APPLETON AND COMPANY, 
NEW YORK. BOSTON, CHICAGO. LONDON. 
