DATA FROM RECENT COMPREHENSIVE STUDIES OF THE PATHOLOGY OF MENTAL RETARDATION ARE ASSEMBLED, INCLUDING MATERIAL ON ETIOLOGY, MORPHOLOGY, BIOCHEMISTRY, AND LABORATORY DIAGNOSIS. AREAS COVERED ARE (1) GENETIC CAUSES OF MENTAL RETARDATION, (2) DISORDERS OF GESTATION, (3) BIRTH INJURY, (4) GENERAL CONSIDERATIONS OF POSTNATAL CAUSES OF MENTAL RETARDATION, (5) GENERAL PATHOLOGICAL ASPECTS, (6) NONSPECIFIC BIOCHEMICAL ABNORMALITIES IN THE BODY FLUIDS, (7) DOWN'S DISEASE, (8) HYDROCEPHALUS, THE PHAKOMATOSES, (9) METABOLIC DISEASES, (10) THE LIPIDOSES AND THE LEUCODYSTROPHIES, (11) AMINOACIDURIAS, (12) OTHER NEUROMETABOLIC DISEASES, AND (13) MISCELLANEOUS CONDITIONS. A TOTAL OF 129 ILLUSTRATIONS IS INCLUDED, AND A BILBIOGRAPHY IS GIVEN FOR EACH OF THE 13 AREAS CONSIDERED. APPENDIXES DESCRIBE AND PROVIDE REFERENCES FOR 21 LABORATORY TECHNIQUES. AUTHOR AND SUBJECT INDEXES ARE PROVIDED FOR THE TEXT. THIS BOOK WAS PUBLISHED BY LITTLE, BROWN AND COMPANY, BOSTON, MASSACHUSETTS 02106, AND IS AVAILABLE FOR $17.50. (JD)