Sir James GrayBorn 14 Oct 1891; died 14 Dec 1975 at age 84.English zoologist who played a leading part in changing the main objective of 20th-century zoological research from evolutionary comparative anatomy to the functional analysis of living cells and living animals, particularly through his editorship (1925-54) of the Journal of Experimental Biology. He authored How Animals Move (1953), and Animal Locomotion (1968). Gray applied mechanical principles to the analysis of animal movement. In 1936, his calculations started a controversy, called Gray's paradox, concerning comparisons of swimming efficiency in fish and in submarines. Energetics calculations suggest that fish and other ocean denizens are much more efficient swimmers than subs, while theoretical hydrodynamic calculations suggest they are not.