Eli S. was born at full term, after a normal delivery, about Jan. 1, 1906. He weighed 3 pounds. His mother noticed, when he was 4 months old, that his lips, cheeks and nails were always blue and that at times he was blue all over. He was feeble from the beginning and, when he was old enough to exert himself, showed dyspnea on exertion. He had scarlet fever when he was 2 and whooping-cough when he was 3 years old. He was brought to the Children's Hospital for the first time Dec. 1, 1909, when he was about 4 years old. At that time he was small, but well nourished. His lips and nails were very blue and the mucous membrane of the mouth was cyanotic. There was marked, general cyanosis when he cried. There was marked clubbing of the fingers and toes and some bulging of the precordia.