PIROPLASMOSIS 



675 



by continued irregular fever, splenomegaly, emaciation, and anaemia, 

 and post mortem showing minute granulomata in the lungs, irregular 

 necrosis and cirrhosis of the liver, the spleen, naked-eye, resembling 

 that of spleno-myelogenous leukemia. In smears from the lung nodules, 

 the liver (Fig. 192), and spleen, stained by Leishman's method, there 

 were observed enormous numbers of small bodies sometimes crowding 

 endothelial cells, often free. These bodies were round or oval and from 

 1 to 4 /i in diameter. Each contained an irregularly placed chromatin 

 mass, the shape of which was globular, oval, or kidney-shaped, the 

 remainder of the parasite consisting of blue-staining basophilic substance. 

 The parasite is surrounded by a non-staining refractile capsule, one-sixth 

 of the diameter of the parasite in width and sometimes containing a 

 single minute chromatoid dot, and similar granules are sometimes seen 

 in the non-chromatoid part 

 of the body of the parasite. 

 Darling considers this or- 

 ganism to be different from 

 the Leishmania donovani in 

 the form and arrangement 

 of its chromatin and in not 

 possessing a blepharoplast. 



PIROPLASMOSIS. 



Up to the present no 

 human disease has been, 

 proved to be associated 

 with the presence of piro- 

 plasmata. But several im- 

 portant diseases of the 

 lower animals are almost 

 certainly caused by proto- 

 zoan parasites of this 

 group, and a short account 

 of the organisms may be 

 given. 



The piroplasmata are 

 pear-shaped unicellular organisms about 



in breadth. The peripheral part is denser than the central, whic 

 often appears as if vacuolated, and at the broad end there is a well- 

 staining chromatin mass. Sometimes irregular and ring-, rod-, or oval- 

 shaped individuals occur. The organisms are found within the red 

 blood corpuscles of the infected animal and also free in the blood. In 

 the former situation there is sometimes only one within a cell, but the 

 numbers vary under different circumstances and in different species. 

 Multiplication takes place by fission, and the new individuals, remaining 

 for longer or shorter times in opposition, account for some of the appear- 

 ances seen in cells. Especially in the forms free in the blood pseudopodial 

 prolongations of the protoplasm, usually from the pointed end, are 

 developed, and it may be by means of such pseudopodia that entrance to 

 the red cells is obtained. Infection is usually carried from infected 

 animals by means of ticks. In one case Koch has described the develop- 

 ment in the organism, in the stomach of the tick, of spiked protoplasmic 

 processes sprouting out from the broad end of the piroplasm, and the 



X 



FIG. 192. Histoplasma capsulatum, section of 

 liver, x 1000. i - 



1 to 1*5 fi long and varying 

 " "ih 



