PARASITE OF KALA-AZAR 



79 



of a possible cycle in an insect host. That this phase of the 

 life history of the parasite may normally be omitted is never- 

 theless quite possible. 



Human Cycle. — After entering the human body, the para- 

 sites probably utilize the blood and lymph streams to obtain 

 transportation to all parts of the body, but do not live free in 





Fig. 14. Parasites of kala-azar, Leishmania donovani; A, isolated parasites 

 from spleen; B, dividing forms from liver and bone marrow; C, spleen cell with 

 parasites; D, group of cells with parasites; E, parasite ingested by leucocyte; F-0, 

 from cultures; F and 6', early stages after ingestion; H, large di'i'iding forms; /, 

 development of flagellum; ,/, small flagellated form; K and L, flagellated Herpv- 

 tomonas forms; M and A^, unequal division; O, parasites resulting from unequal 

 division shown in M and A''. X about 1500. (After Leishman.) 



