I must thank my friend, Professor HANS WEBER, for being, as it were, the prime mover in causing this book to be written. He persuaded me in 1960 to contribute a review to the Ergebnisse der Physiologie. As originally planned, it was to be relatively short. However, the interest and scope of the whole subject of synapses stimulated me to write a much more comprehensive and extensive account. I was not even then satisfied, particularly as so many new and attractive investigations and ideas were being evolved during and after the writing of this review; and during the writing of this book most...