The Comparative Endocrinology of Vertebrates

This volume presents, in 14 chapters by different authors, the formal papers presented at a symposium held at the University of Liverpool in July 1954. The title of the book is taken from the sub-title of the symposia on comparative endocrinology of vertebrates. Each chapter is followed by a page or so of discussion so almost all of the 58 participants at the symposium contributed. Each chapter is followed by a list of references that seem well selected to illustrate major points. No effort has been made to treat the subject in an encyclopedic manner. More extensive review articles are cited to cover general areas of background observation. The format is attractive and readable. The first 113 pages (6 chapters) cover the descriptive aspects of the physiology of reproduction in teleosts, amphibians, reptiles, and birds. One chapter on reproduction in mammals follows. These chapters describe the reproductive phenomena, influences of environmental factors, and variations observed among animals of different species within the orders. A chapter on the evolution of viviparity in vertebrates, "that has been evolved independently many times," is followed by chapters in which results of manipulative experiments are reported and which follow the same outline as the descriptive chapters. In general it is stressed that "endocrine evolution is not an evolution of hormones but an evolution of uses to which they are put.. . ." Ontogenic sequences in mammals are also reported in one chapter. Each author is not only a student of but an outstanding investigator in his area. Knowledge of comparative endocrinology of reproduction of vertebrates is strikingly limited. The diversity of anatomical, physiological, and behavioral modification associated with the two-organism integrationsnecessary in vertebrate reproduction is understood reasonably well in only a few species; "there are 20,000 species of teleosts, only fifty of them, belonging to ten different orders have been studied." The tendency for concern primarily with reproduction in mammals or commercially utilizable birds or fishes, as well as the complexity of structural, functional, and behavioral qualities that require the participation of two separate individuals has limited the expansion of knowledge of reproductive physiology. The symposium reported in this small volume points out much of what is known of the comparative physiology of reproduction but equally as well those areas where the unknown and assumed blend with the observed, interpreted, and known. The problems have been studied "by the building up of an ever-increasing fund of information into a supposedly even more complete picture of how an animal works-an endless job of integrating constantly changing ideas. Others . . . are more interested in breaking down the problem into bits, which can be investigated piecemeal in a simple way. ..."