Abstract
1. There is a lower percentage of positive Wassermanns in cases of malignant disease than in a similar population of non-malignant cases. If buccal cancers are excluded, the percentage is half that in non-malignant cases.2. Cancer of the tongue and buccal cavity, in which a high percentage of positive Wassermanns is found, is almost confined to males and is probably due less to syphilitic infection than to some factor such as smoking.3. There is a low percentage of syphilis in cancer of the digestive tract, except in cases of cancer of the stomach, and the incidence diminishes from mouth to anus.4. Syphilis does not appear to be a factor of importance in cancer of the glandular organs, nor, apart from the lip, in the production of cutaneous cancer.5. In general, from the above figures there is no evidence that syphilis plays any direct or very important part in the production of cancer.