born Dec. 18, 1912, Scranton, Pa., U.S.
died June 9, 1996, Monterey, Calif.
U.S. cell biologist.
He received his Ph.D. from the University of Pennsylvania. His research focused on various aspects of cell reproduction, including mitosis and regulation. He is best known for isolating the structure responsible for cell division, research that he carried out with Katsuma Dan (1905?96) in 1951.