Macleod, John James Rickard (rĭkˈərd) [key], 1876–1935, Scottish physiologist, educated at Aberdeen and Leipzig. He was a professor at Western Reserve Univ. (1903–18) and at the Univ. of Toronto (1918–28) and later taught at the Univ. of Aberdeen. For the discovery of insulin and the studies of its use in treating diabetes he shared with F. G. Banting the 1923 Nobel Prize in Physiology or Medicine. His works include Diabetes (1913), Physiology and Biochemistry in Modern Medicine (with others, 1918; 9th ed. Macleod's Physiology in Modern Medicine, 1941), and Carbohydrate Metabolism and Insulin (1926).