This rare disease may occur in the secondary as well as the tertiary stage of syphilis. In the secondary, it assumes the form of a diffuse, tender swelling, without involvement of the skin; it is relatively not rarely observed in men. The mastitis of the tertiary period mostly affects women; has generally been regarded as gummous and may be present in one or both breasts. As sketched by Neumann1 there springs up during the course of six or eight weeks, swellings as large as a hen's egg, or larger; at first, tense and nodular, a disintegration advancing from the center may reach the skin by extension and cause ulcerative destruction, the defect, perhaps, ultimately becoming replaced by a deep radiating scar. This form is also observed in congenital syphilis. Reinecke2 had the good fortune to examine a syphilitic mastitis after death. The patient, a woman, aged 37, died