Read before the Chicago Surgical Society, March 4, 1938. From the Department of Surgery and the Department of Pathology of the Presbyterian Hospital and from the Rush Medical College of the University of Chicago. This investigation was made possible by a grant from Dr. Ernest E. Irons of the Department of Medicine, Presbyterian Hospital, and of the Rush Medical College of the University of Chicago. 1. Telford, E. D., and Stopford, J. S. B.: Thrombo-Angiitis Obliterans, Brit. M. J. 1:863-866 (April 27) 1935. Averbuck, S. H., and Silbert, S.: Thrombo\x=req- Angiitis Obliterans: The Cause of Death, Arch. Int. Med. 54:436-465 (Sept.) 1934. Allen, E. V., and Willius, F. A.: Disease of the Coronary Arteries Associated with Thrombo-Angiitis Obliterans of the Extremities, Ann. Int. Med. 3:35-39 (July) 1929. Perla, D.: An Analysis of Forty-One Cases of Thrombo-Angiitis Obliterans, with a Report of a Case Involving the Coronaries and the Aorta, Surg., Gynec. & Obst. 41:21-30 (July) 1925. Birnbaum, W.; Prinzmetal, M., and Connor, C. L.: Generalized Thrombo-Angiitis Obliterans: Report of a Case with Involvement of the Retinal Vessels and Suprarenal Infarction, Arch. Int. Med. 53:410-422 (March) 1934. J\l=a\ger,E.: The Pathologic Anatomy of Thrombo\x=req- Angiitis Obliterans in Juvenile Gangrene of the Extremities, Virchows Arch. f. path. Anat. 284:526-583 (May) 1932. Taube, N.: Mesenteric Involvement in Buerger's Disease, J. A. M. A. 96:1469-1472 (May 2) 1931. Barron, M. E., and Lilienthal, H.: Thrombo-Angiitis Obliterans: General Distribution of the Disease, Arch. Surg. 19:735-751 (Oct.) 1929. Brown, G. E.: Thrombo-Angiitis Obliterans, Surg., Gynec. & Obst. 58:297-309 (Feb. 15) 1934. Buerger, L.: Vasomotor and Trophic Disturbances of the Upper Extremities, Am. J. M. Sc. 149:210-229, 1915. 2. Buerger, L.: Thrombo-Angiitis Obliterans: Experimental Reproduction of the Lesions, Arch. Path. 7:381-390 (March) 1929. Horton, B. T., and Dorsey, A. H. E.: Experimental Thrombo-Angiitis Obliterans: Bacteriologic and Pathologic Studies, ibid. 13:910-925 (June) 1932. Rabinowitz, H. M.: Experiments