The biology of mental defect / With a pref. by J.B.S. Haldane. Penrose, L. S. (Lionel Sharples) Medical genetics. People with mental disabilities. Juvenile delinquents. Genetics, Medical. Intellectual Disability etiology. RB155 .P39 616.8 PEB Bibliography: p. 241-264. New York: Grune & Stratton, 1949. 1949. 1949 Text xiv, 285 p. eng