In September, 1977, at a conference organized by Dr. Kenneth McKerns in Northeast Harbor, Maine, USA, I was asked by the Editorial Committee of the Biochemical Endocrinology series to investigate the possibility of organizing the next meeting in France. I proposed a subject which is in the area of my research interest, and this subject was accepted. On arriving back in France, I first looked for an appropriate place for the meeting, and the Chateau de Seillac was chosen in accordance with many objective criteria. We know that all who attended the meeting held in Seillac enjoyed this quiet and charming place in the Loire Valley. The next step was to choose some experts in the field who would contribute to the monograph and present their papers at a conference for the purpose of generating discussions. The action of the local committee, composed of Dr. A. Tixier-Vidal, Dr. Claude Kordon, and me, was crucial in this respect. The local committee proposed the program for the meeting and a list of the majority of contributors to be invited. I wish to thank Dr. Tixier-Vidal and Dr. Kordon for their invaluable assistance.