In the keloid type of leishmaniasis noted by the Sudan Commission epithelial cell nests were characteristic although there was no other evidence of epithelioma. In the American leishmaniasis there is rather constant involvement of the lymphatic glands and often lymphangitis. Histologically the appearance is rather that of granulation tissue with occasionally giant cells. SYMPTOMATOLOGY _Oriental Sore._—Wenyon inoculated a scarified area on his arm which became infected with pyogenic organisms but eventually healed. It was thought that this inflammation would destroy any _Leishmania_ which might have been present. About six months later he became ill and had fever up to 103°F. for a week with malaise and gastro-intestinal upset. At this time a small red papule was noted upon the site of the original scarification which subsequently enlarged and was found to contain leishman bodies. The period of incubation is usually given as about two months, although in some instances it may be as short as a week. Usually the earliest appearance of the sore is similar to that of a mosquito bite. The papule continues to enlarge, becoming purplish in color with a glazed surface. It somewhat resembles an inflamed acne lesion. Growing larger, the surface of the blind boil-like lesions now becomes covered with brownish scales and, either from scratching of the rather pruriginous spot or from the development of vesicles, it becomes covered with a yellowish crust, beneath which is an ulcer with raised edges and discharging a thin offensive pus. The ulceration does not generally occur before the third or fourth month. The ulcer is painless and may be an inch or more in diameter. Healing comes on in about seven to ten months, the yellowish unhealthy granulations giving place to healthy pink ones. The sore tends to run a course of about one year, hence the French designation _bouton d’un an_. According to Weber’s statistics about 85% of the sores were located on the upper or lower extremities and about 10% on the face, while the trunk served as the location for only about 5% of the sores. There are generally 2 or 3 sores. According to Déperet and Boinet the number of sores to a case was one sore in 30%, 2 to 4 sores in 50% and from 4 to 20 in about 20% of cases. [Illustration: FIG. 56.—Oriental sore. (Ruge and zur Verth after Cardamatis.)] _American Leishmaniasis._—Under a number of names such as _espundia_, _uta_, _bubas_ and _forest yaws_ there has been found in many parts of Central and South America an ulcerating sore, more or less resembling oriental sore, but often associated with ulcerating granulomatous lesions of nasal and buccal mucosae. Da Silveira states that in Brazil about 20% of cases develop the mucous membrane lesions. He notes an incubation period of two to three months. In Venezuela the mucous membrane lesions are more rare. The lymphatic glands and lymphatics are commonly affected.