Zavadovskii, Mikhail

Born July 17 (29), 1891, in the village of Pokrovsko-Skorishevo, Elizavet-grad District, Kherson Province; died Mar. 28, 1957, in Moscow. Soviet biologist. Academician of the V. I. Lenin Ail-Union Academy of Agricultural Sciences (1935).

Zavadovskii graduated from Moscow University in 1914. He was chairman of the subdepartment of general biology of the Second Moscow University (1925-28), professor at the First Moscow University (from 1927), and chairman of the subdepartment and head of the laboratory of the dynamics of development of Moscow State University (1930-48). In 1954 he became head of the laboratory of developmental physiology of the All-Union Institute of Animal Husbandry. His principal works dealt with the relationship between embryonic development and environmental factors (chiefly in parasitic worms) and experimental study of the patterns of individual development and reproduction of animals (specifically, analysis of the effect of hormones on the development of secondary sex characters). Zavadovskii formulated the principle of “plus-minus interaction” (intensification of gonadotropic, thyrotropic, or other function of the pituitary gland intensifies the functioning of the corresponding endocrine glands—gonads, thyroid, and so forth; the hormones secreted by these glands inhibit the corresponding tropic function of the pituitary gland). He thus anticipated the application of the cybernetic concept of feedback to individual development. He demonstrated the possibility of experimental multiple births in farm animals, particularly in sheep, and helped to introduce the multiple births method into livestock breeding. Zavadovskii received the State Prize of the USSR in 1946. He was awarded the Order of the Red Banner of Labor.