568 Kala-Azar 



calling it Leishmania donovani, which name has been gener- 

 ally accepted. 



Morphology. As seen in a drop of splenic pulp the organ- 

 ism is a minute round or oval intracellular body measuring 

 2.5 by 3.5 (A. When properly stained with polychrome 

 methylene-blue (Wright's, Irishman's, or Jenner's stains) and 

 examined under a high magnification, it is found that the 

 protoplasm takes a pinkish color and contains two well- 

 defined bright red bodies. The larger of these is ovoid and lies 

 excentrically, its long diameter corresponding to the long di- 

 ameter of the organism. This is regarded as the nucleus. 



Fig. 196. Leishman-Donovan bodies from the spleen of a case of 

 kala-azar. X about 1000. (From Seattle and Dickinson's "A Text- 

 Book of General Pathology," by kind permission of Rebman, Limited, 

 publishers.) 



The second body is smaller and of bacillary shape, and usu- 

 ally lies with its long diameter transverse to the nucleus. 

 This is looked upon as a blepharoplast. It stains more in- 

 tensely than the nucleus. In addition to these bodies the 

 protoplasm may contain one or two vacuoles. 



All of the bodies are intracellular, as can easily be deter- 

 mined by examining sections of tissue, but in smears of splenic 

 pulp the cells are broken and many free bodies may appear. 

 The cells in which they occur are lymphocytes, endothelial 

 cells, and peculiar large cells whose histogenesis is obscure. 

 They are rarely to be found in polymorphonuclear leukocytes, 

 and though there has been much discussion upon this point, 

 probably never appear in the red blood-corpuscles. 



