676 LEISHMANIOSIS 



these lesions contain numerous parasites. It may be said that 

 Thompson and Balfour have described in the Soudan a con- 

 dition in which subcutaneous nodules without ulceration occurred 

 in man, and these contained Leishmania bodies. In South 

 America typical lesions are not uncommon in the nasal mucous 

 membrane, and a similar case has been recorded in the Soudan. 



The close similarities in the morphology and effects of the three 

 Leishmaniae naturally raises the question whether we are not deal- 

 ing with variants of one organism whose differences depend on 

 differences in the virulence of different types or on the suscepti- 

 bility of different hosts. The following are some of the facts 

 bearing on the situation : The Indian and Mediterranean 

 diseases are apparently clinically identical, and while on the one 

 hand in certain parts of India kala-azar is chiefly found in 

 children below the age of fifteen, on the other hand cases occur 

 in young adults in regions where the infantile variety pre- 

 vails. The importance of such factors as racial susceptibility 

 is indicated by the fact that in Tunis it is chiefly the children 

 of Italian parentage who suffer. Kala-azar and Oriental sore 

 are linked by the occurrence in the former from time to time of 

 skin ulcers, although in these, unlike the case of Oriental sore, 

 the parasites are difficult to find. Again, Nicolle found that dogs 

 infected with Leishmania tropica appeared to be less susceptible to 

 Leishmania infantum than usual. The incidence of canine 

 Leishmaniosis in communities where a human infection prevails 

 varies in different regions, e.g., even in the Mediterranean littoral, 

 though it is usually common where Leishmania infantum is 

 found. It may be said that the condition of knowledge regard- 

 ing the inter-relationships of the Leishmaniae does not permit 

 of any definite opinion being expressed at present. Such an 

 authority as Laveran, however, holds the view that the kala-azar 

 of India and that of the Mediterranean are identical with each 

 other and with the disease of dogs, and that Oriental sore is a 

 closely allied condition. 



Histoplasma capsulatum. — Under this name, Darling has described a 

 parasite observed by him in Panama in a case characterised during life 

 by continued irregular fever, spleno-megaly, emaciation, and anaemia,, 

 and post mortem showing minute granulomata in the lungs, irregulan 

 necrosis and cirrhosis of the liver, — the spleen, naked-eye, resembling: 

 that of spleno-myelogenous leukasmia. In smears from the lung nodules,) 

 the liver (Fig. 200), and spleen, stained by Irishman's method, there : 

 were observed enormous numbers of small bodies sometimes crowding' 

 endothelial cells, often free. These bodies were round or oval and from 

 1 to 4 ix in diameter. Each contained an irregularly placed chromatin, 

 mass, the shape of which was globular, oval, or kidney-shaped, the 



