BASED ON A SERIES OF CONFERENCE PAPERS BY VARIOUS AUTHORS, THE BOOK CONSIDERS BOTH EMPIRICAL AND CONCEPTUAL ASPECTS OF LANGUAGE AND MENTAL RETARDATION AND THEIR INTERRELATIONSHIPS. LITERATURE REVIEWS PROVIDE BIBLIOGRAPHIES ON RELEVANT RESEARCH (68 RESEARCH, 1955-66) AND ON LANGUAGE AND MENTAL RETARDATION (149 CITATIONS, 1929-66). FURTHER PAPERS ON THE TOPIC TREAT ASPECTS OF PSYCHOLINGUISTICS, ANIMAL RESEARCH, THE DEVELOPMENT OF COMMUNICATION SKILLS, AND NEUROLOGICAL APPROACHES. EVALUATIVE PROCEDURES FOR LANGUAGE PROCESSES, ISSUES AND ASPECTS, SPEECH AND LANGUAGE TRAINING, AND CLASSROOM GROUPING AND COMMUNICATION ARE DISCUSSED. A SUMMARY INCLUDING DISCUSSION AND RECOMMENDATIONS IS PROVIDED. BIBLIOGRAPHIES APPEAR WITH EACH ARTICLE, AND ALL ARTICLES ARE INDEXED. THIS DOCUMENT WAS PUBLISHED BY HOLT, RINEHART, AND WINSTON, INC., NEW YORK, NEW YORK, AND IS AVAILABLE FOR $6.00. (JD)