Jennings, Herbert S(pencer) (1868–1947)

US protozoologist. He carried out controversial studies on stimulus-response behaviour of unicellular organisms and lower invertebrates, and made major contributions to studies of the genetics and sexual reproduction of protozoa. His speeches and writings on the philosophy of biology were popular with both scientists and nonprofessionals.

He was born in Tonica, Illinois. He held several teaching and research positions before completing his higher education, then studied physics and psychology in Germany 1896–97. He taught at Montana State Agricultural and Mechanical College 1897–98, Dartmouth 1898–99, and was a professor at the University of Michigan 1900–03. He was at the University of Pennsylvania 1903–05, then Johns Hopkins 1906–38. After retirement he lectured and performed genetic research on paramecia at the University of California, Los Angeles 1939–46.