This book is a compilation of articles that were delivered at a conference sponsored by the National Association for Retarded Citizens in October 1973. It represents the first efforts to bring together current information concerning Down syndrome since the publication of the proceedings of a similar conference.1 The current presentation is less comprehensive but nonetheless covers a broad range of topics presented by a variety of researchers and habilitators. Chapters include "Decreased ATPase," "Increased Na +," "Decreased K + in Down's Syndrome Platelets," and "Community Attitudes Toward Down's Syndrome." This change of pace enables the reader to move from the technical material presented by McCoy et al concerning amine uptake into brain synaptosomes to bedtime reading by Edgerton, who discusses community attitudes. Mary Coleman, MD, and colleagues in separate presentations address the question of treatment of Down syndrome with 5-hydroxytryptophan. George F. Smith, MD, provides a major service by presenting a