BRIDGES, CALVIN BLACKMAN Amer ican genetician, was born at Schuyler's Falls, N.Y., on Jan. 11, 1889. In 1912 he graduated at Columbia university where in 1916 he received the degree of doctor of philosophy and was research assistant to T. H. Morgan during 1910 to 1915. From 1915 19 he continued his researches under grants from the Carnegie institution, of whose staff he became a member in the latter year. The chromosome theory of heredity and sex determination engaged his particular attention.