(See Cover)
Above and behind the mouth cavity, tucked into a cradle of bone at the base of the human brain, lies a reddish nugget of tissue, no bigger than a big pea in normal adults—the pituitary gland. Galen, the famed physician of antiquity, and Vesalius, the great anatomist of the Renaissance, knew it. They thought it gave saliva. In 1783 an Irishman named Charles O'Brien died at the age of 22. He was 8 ft. 4 in. tall. A curious physician bought his body for $2,500, dissected the head, found a pituitary gland almost as big as a hen's egg. Modern endocrinologists regard it as the "master gland" of the body.
Scientific research into the pituitary was not pushed until the 1920s, when Herbert McLean Evans of the University of California caused rats to become giants by injecting them with crude pituitary extract. He dwarfed rats by pituitary removal, then with pituitary injections restored them to normal size. He made it clear that the reddish little gland was intimately concerned with one of the most important of biological processes—growth. Since then the veil of ignorance has been gradually lifted.
Last week the American Association for the Advancement of Science held its winter convention in Richmond, Va. With an attendance of 7,000 and 1,800 papers to be presented, the multiple preoccupations of science had to share the spotlight. On hand to see that the pituitary got its share of attention, however, was a pituitary master: Dr. Oscar Riddle of the Carnegie Institution's Station for Experimental Evolution at Cold Spring Harbor, Long Island.
With a great deal of fruitful work behind him on animal pigmentation, on the physiology of reproduction, on the nature and functional basis of sex, and on bionomics,* Dr. Riddle ranks as one of the half-dozen top biologists of the U. S. He also knows more about the pituitary and its functions than anyone else in the U. S., with the possible exception of California's Evans.
At an age (61) when many scientists of bright repute have relaxed their efforts and slipped into the role of inspiring figureheads and advisers to younger men, Oscar Riddle remains in the front line of research.
Dr. Riddle's great contribution to biology is the recognition and analysis of the major pituitary hormone prolactin, discovered in 1932. This substance is the stuff that makes mothers motherly. In Richmond last week Dr. Riddle and two of his ablest co-workers—Robert Wesley Bates, 34, and James Plummer Schooley, 34—summarized their work on prolactin. Dr. Riddle is also, more than any other U. S. biologist, a crusader for the propagation of biologic truth among plain people, and at a dinner for biologists he steamed them up on the opportunities and obligations of biology teachers.
Front Lobe. The pituitary gland consists of three parts, two lobes and a narrow middle. In the smaller rear lobe, two hormones have been fairly well identified (alpha-hypophamine and beta-hypophamine), which appear respectively to influence uterine contractions and blood pressure. Biochemist James Bertram Collip of Montreal's McGill University discovered a hormone of the middle pituitary (appropriately called intermedia) which affects, though it does not exclusively control, the blood sugar level.