570 Kala-Azar 



later, as they grew larger, a flagellum was thrust out at one 

 end. 



Distribution. The Leishman-Donovan body is widely 

 distributed throughout the body of the patients suffering 

 from kala-azar. It occurs in great numbers in the cells of the 

 spleen, of the liver, of the bone-marrow, and in the ulcerations 

 of the mucous membranes and skin. In the peripheral blood 

 they are few and only in the leukocytes. They are always 

 intracellular, or when in the circulating blood may be found 

 in indefinite albuminous masses, probably destroyed cells. 

 The number in a cell varies up to several hundred, such great 

 aggregations only being found in the peculiar large cells of 

 the spleen. 



Lesions. The splenomegaly is the most striking lesion. 

 The change by which the enlargement is effected is not spe- 

 cific. The organ is not essentially changed histologically, but 

 seems to be merely hyperplastic. The liver is enlarged, but 

 here, again, specific changes may be absent. In some cases 

 a pallor of the centers of the lobules may depend upon 

 numbers of parasite-containing cells, partly degenerated. 



The yellow bone-marrow becomes absorbed and red tissue 

 takes its place, as in most profound anemias. 



Transmission. Roger's observation, that the round 

 bodies grew into flagellate bodies at temperatures much below 

 that of the human body, led Manson to conjecture that the 

 extra-human phase of the life of the organism took place at 

 similar low temperatures in the soil or in water. Patton* 

 found that a number of cases sometimes occurred in the same 

 house, while neighboring houses were free, and thought this 

 suggested that a domestic insect might be the distributing 

 host. He made some unconvincing experiments on the sub- 

 ject. Rogers tried to convict the bedbug, but also failed. 

 The rarity of the Leishmania in the peripheral blood seems 

 opposed to its transmission by insects. 



On the other hand, the organisms leave the body in con- 

 siderable numbers in the dejecta of patients suffering from 

 ulcerative lesions of the intestines and in the discharged pus 

 from the ulcerations of the skin. 



However, in the present state of knowledge there can be 

 nothing but speculation upon the subject. The disease ap- 

 pears not to be transmissible to any of the laboratory animals, 



* "Scientific Memoirs of the Government in India," 1907, No. 27. 



