Bridges, Calvin Blackman, 1889–1938, American geneticist, b. Schuyler Falls, N.Y., grad. Columbia (B.S., 1912; Ph.D., 1916). In his research he collaborated with T. H. Morgan, A. H. Sturtevant, and H. J. Muller, the group that developed many of the concepts of modern genetics through their study of the fruit fly, Drosophila. He continued with the Morgan group as a research associate of the Carnegie Institution in Washington from 1919. His contributions to modern genetics include the proof of the chromosome theory of heredity, formulation of the theory of genic balance, and the detailed study of giant salivary chromosomes in relation to the positions of genes. He was coauthor of The Mechanism of Mendelian Heredity (1915).