THE Hv'FlMOFLAGELLATES. 



259 



two. The former is, when round or oval, from 2 — 3| /n in 

 diameter,' when pyriforni from 3i — 4 /,t in length by 1^ fx or 



^ <^ <^ ^ .^ 

 b.: 



L: 



3. 



m 





Fig. 37. — I. Piroplasma donovani (Lav. and Mesn.) : a, 

 typical pear-shaped or oval forms ; h, various stages in longitu- 

 dinal division; c, nuclear division preparatory to multiple fission ; 

 d, endoglobular forms, in red blood-corpuscles (j? = pigment 

 grains); e, bacillary form of tlie parasite in a corpuscle; M. 

 = large macrophageal cell with many parasites. (After Donovan.) 



II. Uninuclear leucocyte (L) containing several parasites. (After 

 L. and M.) 



III. P. (Helcosoma) tropicum (Wright). rt, single indi- 

 viduals ; h, dividing forms. (From Mesnil, mostly after Wright.) 



IV. P. donovani in cultures of different ages, a, ordinary 

 forms of varying size ; h, c, stages in multiple division; d, binary 

 fission; e,f, and g, flagellate forms. (After Rogers.) 



slightly more in breadth. The forms from tropical ulcers 

 average about 4 ju by 3 ju (fig. o7 III). The body is, most pro- 



' Laveran and Mesnil describe those occurring in the peripheral blood as 

 being much smaller, and probably young forms j this may account for their 

 being frequently overlooked. 



