I. P. Pavlov and W. B. Cannon: founders of modern physiological thought relative to behavior and the autonomic nervous system.

It was almost a half century ago that I last attended an International Congress in Moscow and Leningrad--the IUPS Congress of 1935. My wife and I traveled far and saw the majesty of this land and its peoples. Here I met the great Pavlov and heard him present his thoughts concerning the conditioning of behavior. Cannon presented his concepts of transmitters and receptors. There were many other famous physiologists present, A. V. Hill and Lord Adrian; Kato of Japan demonstrated single nerve fiber studies. Someone talked of conditioned diuresis; I read a paper on hypothalamic control of the hypophysis. That was the dawn of neuroendocrinology, studies of hypothalamic function, sensory receptors, and the transmitter-receptor era. It was, like now, a time of great scientific endeavor, but there were clouds in the sky--Stalin and Hitler were coming to power, but the U.S.S.R. and America were friends, and in science it is still so. I wonder what some young man here will be able to report 50 years from now.