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mammary gland

(Encyclopedia)mammary gland, organ of the female mammal that produces and secretes milk for the nourishment of the young. A mammal may have from 1 to 11 pairs of mammary glands, depending on the species. Generally,...

Houssay, Bernardo Alberto

(Encyclopedia)Houssay, Bernardo Alberto bārnärˈdō älbārˈtō ouˈsī [key], 1887–1971, Argentine physiologist, b. Buenos Aires. He was a child prodigy, entering college at the age of 9 and becoming a hospit...

Cohen, Stanley

(Encyclopedia)Cohen, Stanley, 1922–2020, American biochemist, b. New York City, Ph.D. Univ. of Michigan, 1948. Cohen did his most important work at Washington Univ. with Rita Levi-Montalcini in the 1950s. Studyin...

Huggins, Charles Brenton

(Encyclopedia)Huggins, Charles Brenton, 1901–97, American surgeon and urologist, b., Halifax, N.S., M.D. Harvard Univ., 1924. He was a professor at Arcadia Univ. at the time of his retirement in 1979 but spent th...

thirst

(Encyclopedia)thirst, sensation indicating the body's need for water. Dry or salty food and dry, dusty air may induce such a sensation by depleting moisture in the mucous membranes of the mouth and throat. Relief t...

castration

(Encyclopedia)castration, removal of the sex glands of an animal, i.e., testes in the male, or ovaries and often the uterus in the female. Castration of the female animal is commonly referred to as spaying. Castrat...

Romer, Paul Michael

(Encyclopedia)Romer, Paul Michael, 1955–, American economist, b. Denver, Ph.D. Univ. of Chicago, 1983. He has taught at the Univ. of Rochester (1982–88), Univ. of Chicago (1988–90), Univ. of California at Ber...

Banting, Sir Frederick Grant

(Encyclopedia)Banting, Sir Frederick Grant, 1891–1941, Canadian physician, M.D. Univ. of Toronto, 1922. From 1923 he was professor of medical research at Toronto. Working with C. H. Best under the direction of J....

annual rings

(Encyclopedia)annual rings, the growth layers of wood that are produced each year in the stems and roots of trees and shrubs. In climates with well-marked alternations of seasons (either cold and warm or wet and dr...

growing season

(Encyclopedia)growing season, period during which plant growth takes place. In temperate climates the growing season is limited by seasonal changes in temperature and is defined as the period between the last killi...