LEISHMAN-DONOVAN BODY 597 



covering with a cover-glass one edge of which rests on a bristle 

 to avoid pressure. 



(3) Permanen^ mounts may be made by the Heidenhain 

 method. 



(4) Films may be made in the ordinary way, and stained with 

 weak carbol-fuchsin or Leishman's stain. (The organisms are 

 apt to be distorted. ) 



(5) The following method, devised by Rousselet (Journ. 

 Quekett Microscop. Club, 2nd series, vol. vi, No. 36, p. 5, March, 

 1895), for preserving Rotatoria, may be tried. In those forms 

 which are non-contractile, kill by adding a drop of per cent, 

 osmic acid, wash immediately in water, and preserve in 2| per 

 cent, formalin. Contractile forms may be first narcotised by 

 adding a drop or two of 2 per cent, cocaine solution, then killed 

 with the osmic and preserved as before. 



Leishmaniasis 



This term is applied to a group of diseases caused by 

 a similar parasite and widely distributed in tropical and 

 sub-tropical countries of the Old and New World. 



In kala-azar, or tropical splenomegaly, a disease met 

 with in India, Assam and the East, a small parasite, the 

 Leishman-Donovan body, occurs in large numbers in the 

 spleen and liver, also in the lymphatic glands, lungs, and 

 intestinal submucosa, and in large mononuclear leucocytes 

 and endothelial cells. The bodies are small (2-3 /x) round, 

 ovoid, or oat-shaped masses of protoplasm, apparently 

 encapsuled, and contain two chromatin masses, one large 

 and oval, staining pale red with Leishman's stain, the 

 other small and rod-shaped, and staining deep red with 

 Leishman (Fig. 55, a). They sometimes occur in masses 

 (Fig. 55, c). Leishman considered the bodies to be degene- 

 rate trypanosomes, but the organism is now considered 

 to belong to a distinct genus, and is termed Leishmania 

 Donovani. Rogers succeeded in cultivating it in citrated 

 blood at 20-25 C., in which it develops into a flagellated 



