670 



LEISHMANIOSIS 



cells and the process is repeated. The clusters of bodies some- 

 times seen in smears are probably held together by the remains 

 of ruptured phagocytes. In capillaries the endothelial cells after 

 phagocyting the bodies probably become detached from the 

 capillary wall, as they are often observed free in the lumen of 

 the vessel this being well seen in the hepatic capillaries. 

 In the body generally the parasites are found in greatest 

 abundance in the spleen, liver, and bone marrow, and also in 

 mesenteric glands, especially in those draining one of the 

 intestinal ulcers ; less frequently they occur in the skin ulcers, 

 and in other parts of the body. Donovan described them as 



occurring in the peri- 



.^AflHBfe^^^ pheral blood, especially 



sy. , within the leucocytes, 



and this has been con- 

 firmed by other observers, 

 though sometimes pro- 

 longed search is neces- 

 sary. Patton has found 

 that the numbers in the 

 blood vary from time to 

 time, and special incur- 

 sions may be associated 

 with exacerbations of 

 dysenteric symptoms 

 which he holds indicate 

 a spread of the intestinal 

 ulceration. 



In the body the para- 

 site multiplies by simple 

 fission, both nuclei divid- 

 ing amitotically, and two new individuals being formed ; but 

 sometimes a multiple division takes place, each nucleus dividing 

 several times within the protoplasm and a corresponding number 

 of new parasites resulting. 



In view of Leishman's original opinion an extremely important 

 discovery was made by Rogers and later confirmed by Leishman 

 himself, to the effect that in cultures a flagellate organism 

 developed from the Leishman-Donovan body. Cultivation was 

 effected by taking spleen juice containing the parasite, placing it in 

 10 per cent, sodium citrate solution and keeping it at 17 to 24 C. 

 Under such conditions there occurs an enlargement of the 

 organism, but especially of the larger nucleus. This is followed 

 by the appearance of a pink-staining vacuole in the neighbour- 



FIG. 191. Leishman-Donovan bodies within 

 endothelial cell in spleen. See also Plate 

 VI., Fig. 24. x]000. 



