The gummas form the most important features of syphilis, at least from a surgical standpoint, since they frequently appear in the depths as well as on the surface of the body, without any other symptoms, and they often cause no little perplexity in diagnosis. Syphilomas, tuberculous gummas, phlegmons, innocent and benign tumors, as occurring especially in and upon the bone, in the muscles, tongue, the breast, the testicle, and elsewhere, may be difficult of diagnosis. Of course, a history of syphilis is a great help. Doubt frequently arises when such a history cannot be obtained. Scarcely any other disease will produce multiple lesions such as are seen in syphilis, and when multiple they are usually distributed, with some appearance of symmetry. Ulcers formed by their breaking down are often extremely sensitive, but do not bleed easily, nor show a tendency to exuberant granulation. In cases of doubt the most successful test is perhaps the therapeutic, and consists in giving mercurial or mixed treatment to the point of toleration and noting its effect. [Illustration: FIG. 26 Tuberculous serpiginous syphilide resembling lupus vulgaris. (Fordyce.)] [Illustration: FIG. 27 An ulcerating gumma of the leg. (Fordyce.)] In many patients, especially of the hospital class, scars, which are strongly suggestive, will be visible upon the legs. It does not follow, however, that an old scar upon the legs, even if surrounded by a pigmented area, is necessarily of syphilitic origin. Old ulcers of the limbs are frequently seen in connection with varicose veins, and may show exceedingly chronic tendencies; moreover, it is possible for chronic and non-specific ulcers to occur in old syphilitic subjects when the course of the local lesions may be influenced by the old affection, although they are not specific ulcers. Benefit, however, will in such cases accrue by the reasonable administration of antispecific treatment, but it should be combined with suitable local measures. =The Vascular System.=--The lesions which are encountered in the bloodvessel walls in chancre and early syphilis have been described. The heart and vessels are liable to suffer, as they contain connective tissue. Gummas have been noted in the heart, while the poison also may produce thickening of the valves, and disease of the coronary arteries, the endocardium and the myocardial structure.