Elementary genetics / by W. Ralph Singleton. Drawings by Te-hsiu Ma. Singleton, W. Ralph (Willard Ralph), 1900- Genetics. QH431 .S64 1967 575.1 SIE Includes Index. Includes bibliographies. Princeton, N.J. : Van Nostrand, c1967. c1967. 1967 Text xii, 576 p. : eng