The present title Mammalian Endocrinology provides a definitive and comprehensive Review of all aspects relating to hormones in different Animals including wild and Democratic species. It discusses the intimate Physiology of the Endocrine system itself and describes the role of hormones in the processes of nutrition, osmoregulation, Colour change, Calcium Metabolism and reproduction. Subject matter has been presented in a readable way emphasizing the differences between Species from a functional aspects.