KALA-AZAR 565 



The other chromatin body is usually rod-shaped, and is set 

 perpendicularly or at a tangent to the larger mass, with which 

 only exceptionally it appears to be connected. Usually the 

 protoplasm contains one or two vacuoles. Though in spleen 

 smears many free bodies are seen, the study of sections shows 

 that ordinarily their position is intra-cellular, the cells con- 

 taining them being of a large mononuclear type (Fig. 171). The 

 view held is that on their entering the circulation they are 

 taken up by the mononuclear leucocytes and by such cells as 

 the endothelial lining of the splenic sinuses or by those lining 

 capillaries or lymphatics, that in these cells multiplication takes 

 place it may be to such 

 an extent as to rupture 

 the cell, and that if 

 thus the bodies become 

 free, they are taken up 

 by other cells and the 

 process is repeated. The 

 clusters of bodies some- 

 times seen in smears are 

 probably held together 

 by the remains of rup- 

 tured phagocytes. In 

 capillaries the endothelial 

 cells after phagocyting 

 the bodies probably be- 

 come detached from the 



capillary wall, as they 



J . ' -i FIG. 1/1. Leishman-Douovan bodies within 



are otten observed tree endothelial cell in spleen, x 1000. 



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. Whether they can be demon- 

 strated microscopically in the blood is disputed. Donovan 

 described them as occurring in the blood, and also as being 

 present within red blood corpuscles, but though Laveran agreed 

 with Donovan's description, the observation has not been 

 confirmed by other observers. 



In the body the parasite multiplies by simple fission, both 

 nuclei dividing amitotically, and two new individuals being 

 formed ; but sometimes a multiple division takes place, each 



