This book is intended to serve as a text for beginning students in universities and colleges, or for students who have already taken a course in general biology and wish to gain a more comprehensive view of the animal kingdom. It differs from many of the college text-books of zoölogy now on the market in several important respects: (1) the animals and their organs are not only described, but their functions are pointed out; (2) the animals described are in most cases native species; and (3) the relations of the animals to man are emphasized. Besides serving as a text-book, it is believed that this book will be of interest to the general reader, since it gives a bird’s-eye view of the entire animal kingdom as we know it at the present time. Within the past decade there has been a tendency for teachers of zoölogy to pay less attention to morphology and more to physiology. As a prominent morphologist recently said, “Morphology ... is no longer in favor ... and among a section of the zoölogical world has almost fallen into disgrace” (Bourne). The study of the form and structure of animals is, however, of fundamental importance, and is absolutely necessary before physiological processes can be fully understood; but a course which is built up on the “old-fashioned morphological lines” is no longer adequate for the presentation of zoölogical principles. The present volume has not been made by merely adding a description of the vertebrates to the author’s “Introduction to Zoölogy” (for a brief account of which see the last pages of this circular). On the contrary, it is a new work throughout, although the same general method of treatment, which proved so successful in the earlier book, has been employed in this one. Similarly, in the preparation of this book the author has submitted the manuscript of each chapter to a scholar and teacher of unquestioned authority in the particular field. The criticisms and suggestions thus secured have greatly increased both the accuracy and the practicability of the text. THE MACMILLAN COMPANY =Publishers= =64-66 Fifth Avenue= =New York= An Introduction to Zoölogy By ROBERT W. HEGNER, Ph.D. Instructor in Zoölogy in the University of Michigan _Illustrated, 12mo, $1.90 net_