METCHNIKOFF, ELIE (1845–1916), Russian biologist, born at Ivanovka, near Kharkov. Metchnikoff 's father was an officer of the Imperial Guard; his mother was Jewish (her family name was Neakovich). After graduating from the University of Kharkov he went to Germany for further training in biology. A succession of important discoveries in embryology earned Metchnikoff a reputation for originality and acuteness of observation, and in 1870 he was appointed professor extraordinarius at the University of Odessa.
The political upheavals and persecution of the Jews that followed the assassination of Czar Alexander II led Metchnikoff to leave Odessa in 1882. He went to Messina, a place especially favorable for the study of marine organisms. Here, during the course of studies on jellyfish and sponges, he began to turn his attention to the remarkable behavior of certain amoeba-like cells that ingest and destroy foreign particles in the body. Metchnikoff developed the theory that these cells, which he named "phagocytes," served to engulf and digest bacterial invaders of the organism. He set forth this thesis in an essay "The Struggle of the Organism Against Microbes" (1884).
In 1888 Pasteur invited him to Paris and gave him a laboratory at the Ecole Normale. When the Pasteur Institute was established, Metchnikoff became its subdirector. To this laboratory Metchnikoff attracted large numbers of investigators, whose research established the validity of the phagocytosis theory.
Metchnikoff later became interested in the problems of biological aging. In Etudes sur la nature humaine (1903; The Nature of Man, 1904) he advanced the idea that senile changes result from toxins produced by bacteria in the intestine. To prevent these "unhealthy fermentations," Metchnikoff advocated the inclusion of sour milk in the diet. In 1908 Metchnikoff shared the Nobel Prize for medicine with Ehrlich for his work on immunity.
O. Metchnikoff, Life of Elie Metchnikoff, 1845–1916 (1921), incl. bibl.; H. Zeiss, Elias Metschnikow, Leben und Werk (1932), incl. bibl.; A. Besredka, Histoire d'une idée (1921); T. Levitan, Laureates, Jewish Winners of the Nobel Prize (1960), 111–5.