1905.] Kcda-Azar, etc., from Leishman- Donovan Bodies. 289 



pear-shaped, and their flagella shorter, as in figs. 2 to 6 of Line VI, thus 

 showing a tendency to reversion towards the undeveloped spleen stage of the 

 parasite, only all stages of the degenerative process were present at the same 

 time, and many of the shrunken badly staining forms were disintegrating. 

 During this process the flagella were often shed, and with it the micro- 

 nucleus came away, although a narrow non-staining space was still visible 

 between the two, as shown in fig. 10, clearly proving an organic connection 

 between the flagellum and the micronucleus or blepharoplast. Within three 

 days all the rosettes of flagellates had broken up into granular masses and 

 their identity completely lost. The degenerative changes in this hepatomonas 

 are therefore very similar to those, which have been described in the. case of 

 trypanosom.es. 



The Relationship of Leucocytes to the Parasites in Cultures. 



Although it is doubtful as yet whether the Leishman-Donovan bodies can 

 be found in the peripheral blood either free or in the red corpuscles, yet both 

 Donovan (4) and ( 'lnistophers(13) have found this stage of the parasite 

 within leucocytes in the circulating blood during high fever, the latter 

 having twice found a number of them, nearly all within polymorphonuclears, 

 during a differential count of 500 leucocytes, which would mean an enormous 

 number within the peripheral circulation at one time, and amply suthcient to 

 infect a blood-sucking insect if such proved a suitable host. It is therefore 

 of interest to determine if the parasites can develop in acid cultures within 

 leucocytes. Figs. 7 and 8 illustrate conditions bearing on this point, the 

 former representing a polymorphonuclear on the second day of the culture, 

 which contains typical parasites, although they are somewhat less developed 

 than those shown beneath it from the same slide ; the latter shows another 

 degenerating leucocyte from the same culture on the following day, in which 

 some of the parasites are clearly much enlarged and developing typically, if 

 somewhat more slowly, than those show outside the corpuscle, while others 

 are degenerating and staining feebly. It appears then that development 

 may proceed within leucocytes, while Christophers is also of opinion that it 

 occurs within macrophages in cultures, so biting insects might be infected by 

 the leucocytes containing the undeveloped parasites which have been found 

 in the peripheral blood. 



The way in which the polymorphonuclears especially take up the parasites 

 in the peripheral blood is also of great interest in connection with the 

 extreme decrease in these corpuscles, for I have shown that they are 

 commonly decreased a tenth of the normal number, while in the latter stages 

 of the disease ; in children especially, they may fall to only from one- 



