This book is the proceedings of two symposia, on Proteins of International Society of Neurochemistry in Budapest, July 1971. If confirmation of the utility for such a book was needed, it was obtained with the independent publication of a review on Proteins of the Nervous System (1) covering essentially the same ground. This review is an excellent collection of the earlier literature. The present volume summarizes the more recent advances in this field, and in addition covers those areas, glycoproteins and peptide hydrolases, which were not dealt with by Shooter and Einstein (1).