This book has been written primarily for use as a textbook by undergraduate, as well as graduate, students. It is hoped that it may serve as a basis for course work in comparative endocrinology and also as an auxiliary text to aid in the teaching of comparative animal physiology. In order to gain the most from this book, the reader should have a basic knowledge of zoology and animal physiology. I have nevertheless attempted to put the endocrinology that is described into a broader biological framework by relating it to the animal's physiology, ecology, and evolutionary background. This is one of the reasons why I have departed from the more usual format of previous textbooks in this area, which generally deal with each endocrine gland in succession, chapter by chapter. Instead, I have attempted to describe certain broad and basic biological processes, the functioning of which is often coordinated by the secretion from several endocrine glands.
No attempt has been made to describe invertebrate endocrinology, as the rapid growth of this area really justifies a separate textbook. The book by K. G. Highnam and L. Hill (Comparative Endocrinology of the Invertebrates, Elsevier: Amsterdam, 1970) deals admirably with this subject.
It has not been possible in a book of this nature to give a complete list of original references. There are far too many of these, and many of the earlier observations are already a part of the “classical literature”. Instead, I have attempted to refer the reader to more recent papers and reviews that contain references to the material described and can act as useful “starting points” for the students who wish to study the subject further. In order to keep abreast of developments in the various subject areas described, the current literature should be consulted. The principal Journals where papers on these subjects are published are General and Comparative Endocrinology, Journal of Endocrinology, Endocrinology, and Comparative Biochemistry and Physiology. In addition, many papers appear in the Standard physiological Journals, espeäally Journal of Physiology and American Journal of Physiology.