The third edition of this popular textbook retains the successful format of previous editions, dealing with the nature, actions and roles of hormones among vertebrate animals. Special emphasis is placed on the evolution and origins of hormones and their receptors, on the role of hormones in the physiological coordination of vertebrates, and on dealing with each endocrine process in the context of the organism's physiology, ecology and evolution. Comparative Vertebrate Endocrinology discusses the intimate physiology of the endocrine system and the pivotal role of hormones in coordinating basic body processes such as nutrition, reproduction, calcium metabolism and osmoregulation, as well as their contributions to animal coloration, molting and development. The species included range from lower chordates through to mammals, including marsupials.