I have had the privilege of conversing with Professor palladin on numerous occasions during the last 15 years of his life. In these years, after the age at which most people retire, he was still a most admirable man, with an active interest in science, and a wide and wise approach to its many facets. I was always impressed by his enthusiasm for, and lm. owledge about, studies of the nervous system, both his own and those of others. He was interested in myriads of details, which he was able to synthesize into concepts and systems. The present book reflects, in addition to his warmth and wit and wisdom, Dr. Palladin's approach and style: how he and his collaborators came to their conclusions after careful consid­ eration of all the facts. The references in this book, for example, show the great number of works that were found worthy of quoting and including. The reader can see the stepwise emergence of a concept as he reads the pages of this book. Facts are not given for facts' sake, but to try to present a picture based on a large number of observations, by most of the scientists who studied this aspect of the nervous system. The work emerges as from a community; there is ·no attempt to minimize results of others or to maximize those of Palladin's laboratories. Palladin's working lifespan covered over six decades, and many stages in biochemistry.