As a former president of the International Society for Neuro vegetative Research and as a co-editor it is a pleasure to write a short introduction to the present volume which contains the proceedings of an international symposium, held at Tihany, Hungary, June 19-24, 1972, under the auspices of the Society mentioned above. The meeting, which was organized by Professor B. Csillik, Szeged, Hungary, who also acted as president, took place at the Tihany Biological Institute, most beautifully situated at lake Balaton. Such international symposia of the International Society for Neurovegetative Research have been organized at irregular intervals in several different countries. Members of the International Society are, automatically, the members of National Societies for Neuro vegetative Research, active in some European countries and in Japan, as well as individuals taking interest in the aim of the International Society. From its foundation, in 1953, on the goal of the Society has always been the advancement of neurovegetative research as per formed by both, workers in the basic sciences and medical prac titioners doing scientific work. Therefore, symposia of the Inter national Society for Neurovegetative Reseanh are international forums where pure scientific work as well as clinical investigations and clinical experience can be discussed. In this way, the Society has always been trying to bridge the gap between pure and applied science in the medical field which is so often felt to exist, especially at the present time often suffering from overspecialization.