KALA-AZAR 



that the human parasite belongs to the flagellates." 

 Rogers's observations have been confirmed by others, 

 including Leishman (fig. 49). 



The flagellate organism into which the Leishman 

 body develops differs from a true trypanosome in that 

 it does not possess an undulating membrane, and that its 

 flagellum and micronucleus are situated at the blunter, 

 posterior end of the parasite. It thus resembles a herpeto- 

 monas. Similar forms have, however, been observed 

 in the so-called cultivations of true trypanosomes, and 

 Rogers noticed forms in his cultures similar to those 



z 

 V 



FIG. 49. a, Trypanosomes and the altered forms found in culture ; b, Leish- 

 man-Donovan bodies and the altered forms found in culture. 



described by Bradford and Plimmer as occurring in the 

 lungs of animals artificially infected with Trypanosoma 

 brucei. 



Mention may be made of the opinion expressed by 

 Laveran and Mesnil that the Leishman body is a piro- 

 plasma, and of Ross's suggestion that it belongs to a new 

 genus which he named Leishmania, calling the parasite 

 Leishmania donovani. Both these opinions, however, 

 were expressed before the development into flagellate 

 forms had been observed. Rogers found that when the 

 blood obtained by spleen puncture of patients suffering 

 from kala-azar was mixed with sterile sodium citrate 

 solution, and kept at a temperature of 22 C. for a few 

 days, developmental forms occurred. The cytoplasm of 



