1. Syphilitic aortitis is a productive inflammatory process, the earliest and 
most constant feature of which is a perivascular round cell infiltration in the 
adventitia. 2. The typical gross picture of luetic aortitis is often obscured by 
a superimposed, diffuse atherosclerosis. In the early cases the aorta appears 
fairly normal, presenting only the characteristic histological changes. 3. A 
pure aortic insufficient valve, with the exception of an infectious 
endocarditis, is always luetic. 4. Cardiac hypertrophy is not a complication of 
luetic aortitis. When present it is usually associated with a nephritis. 5. The 
demonstration of Spirochoeta pallida, even in advanced specimens of syphilitic 
aortas, is doubtful. 6. An antigen prepared from alcoholic extract of guinea pig 
heart with the original Wassermann technique should be preferred in diagnosing 
luetic aortitis. 7. Positive complement fixations in patients suffering with 
syphilis for a period of about fifteen years or longer suggest the probability, 
at least, of histological luetic changes in the aorta in 80 to 90 per cent of 
the cases. 60 per cent of these die from aortitis. 8. About 94 per cent of 
patients suffering with aortitis give positive Wassermann reactions.