Department of Biochemistry and Molecular Biophysics, and Department of Obstetrics and Gynecology, Columbia University, New York, New York 10032, U.S.A. The lecture was given during the 5th Joint Meeting of British Endocrine Societies in Sheffield on 10 April 1986 It is impossible for me to express adequately my deeply felt gratitude to the Selection Committee of the Society for Endocrinology for having chosen me to be the Sir Henry Dale Medallist for 1986. An accolade from one's peers is the supreme award. To add this recognition to the many years of enjoyment that came to me–and still come to me–from my adventures among the steroids is to provide me with a glorious exhilaration. And on top of that, to be allowed to join the group of distinguished scientists who were the previous Dale Medallists is a great privilege and honour. It is fitting that I acknowledge my gratitude to you.