General Increase.— There is rather general agreement that the incidence of bronchiogenic carcinoma has greatly increased in the last half-century. Statistical studies at the Charity Hospital of New Orleans (Ochsner and DeBakey),1the St. Louis City Hospital (Wheeler)2and the Veterans Administration Hospital of Hines, Ill. (Avery)3have revealed that at these hospitals cancer of the lung is now the most frequent visceral cancer in men. Autopsy statistics throughout the world show a great increase in the incidence of bronchiogenic carcinoma in relation to cancer in general. Kenneway and Kennewat,4in a careful statistical study of death certificates in England and Wales from 1928 to 1945, have presented undoubted evidence of a great increase in deaths from cancer of the lung. In this country statistics compiled by the American Cancer Society show a similar trend during the past two decades.5 Tobacco as a Possible Cause