The effect of short periods of simple anoxia uncomplicated by the accumulation of carbon dioxide or by anesthetics has been studied in experiments on progressive thrombosis since the beginning of 1937. The experimental procedure employed was briefly denoted as anoxic shock. Steadily flowing oxygen-nitrogen mixtures in which the oxygen was gradually reduced produced a slowly but progressively increasing anoxia, which caused, within fifteen to thirty minutes, a state of gasping respiration or the arrest of respiration. The symptoms elicited were so much like those described by observers of Sakel's1 insulin shock that in his detailed report on insulin shock, given at the staff meeting of the Memorial Hospital, Albany, N. Y., on Nov. 23, 1937, Dr. W. B. Cornell seemed to describe all the symptoms I had observed in rabbits during anoxic shock. I was so impressed that in the discussion which followed I dared to say that I