Blakeslee, Albert Francis, 1874–1954, American botanist, b. Genesee, New York. He received his Ph.D. at Harvard (1904) and was a member of the faculty until 1907. After several years as professor at Connecticut Agricultural College (now the Univ. of Connecticut), he joined the staff of the Carnegie Institution of Washington at Cold Spring Harbor, N.Y., and later served as its director (1936–41). In 1943 he became director of the Smith College Genetics Experiment Station. From his earliest research, the discovery of sexual reproduction in bread molds, his contributions to botany and genetics were of far-reaching significance. His study of the inheritance and geographical distribution of the jimson weed, Datura, provided important information concerning chromosome behavior, genic balance, and species evolution. He introduced the use of the alkaloid colchicine to increase the number of chromosomes in the plant cell.