DELAGE, YVES

born May 13, 1854, Avignon, Fr. died Oct. 7, 1920, Sceaux French zoologist known for his research and elucidation of invertebrate physiology and anatomy. He also discovered the equilibrium-stabilizing function of the semicircular canals in the inner ear (1886). Delage became a member of the zoology staff at the Sorbonne in 1880 and at Caen, Fr., in 1881; he became director of the zoological station at Luc in 1884, titular professor of zoology at the Sorbonne in 1886, and director of the marine zoological station at Roscoff in 1878 and 1902. Delage studied circulation in crustaceans, made important discoveries in the embryology of sponges (such as Sacculina), and investigated the nervous system of barnacles (Peltogaster) and flatworms (Convoluta). He developed a method for culturing sea urchins following artificial fertilization of the eggs with chemicals. Turning late in his career to more general problems of biology, he considered how life in individual organisms and species is manifested through cytoplasm, and he examined mechanical problems of the cell. His writings include La Structure du protoplasma, les thories sur l'hrdit et les grands problmes de la biologie gnrale (1895; The Structure of Protoplasm, the Theories of Heredity and the Great Problems of General Biology) and Trait de zoologie concrte, 6 vol. (18961903; Treatise of Pure Zoology).