That syphilis plays an important rôle in the causation of aortic aneurysm and aortitis had been long suspected. Weil thought that every case of fibrous aortitis was due to syphilis. Groen studied 306 cases of visceral syphilis and found vascular changes in 76 per cent. of the men and 49 per cent. of the women. Schultze holds syphilis to be the cause of aortitis in practically all cases. Hampeln says, "A definitely diagnosed, circumscribed aneurysm permits the assumption of luetic infection, eight to twenty years previously." Etienne believed 70 per cent. of all aneurysms to be syphilitic in origin; Gerhardt put the percentage at 53, and A. Frankel at 55. The pathologic work of Doehle, Heller and his pupils, Stadler, Chiari, Benda, Marchand and Eich in Germany; of Mitchell Bruce in England, and the clinical studies of Huchard and Dieulafoy in France, have emphasized the syphilitic origin of aortitis and