oS 



SOMK OHSKRVATIONS ON Tl! Yl'ANOSO^r A ItlUCKI ? (rKCAmi' 



SiilxiiUiiri' 

 successful 



Appearance 

 of a 



herpetomonad 

 type in culture 



DifBculty in 

 culture 

 altempLs «iili 

 T. tviini 



From 72 linurs oiiwiiiils lliLrc wiis a proj^ressivo decioasc In tlio luiiiiljcf of 

 ti-vj)aiu)somes, their niovi'iiii'iits l)cinj{ more rotatory in nature and very slugyish. The 

 clumps disappeared entirely and tliose trypanosonies present on the eighth and sixteenth 

 days, in hoth media, reacted very feebly to ]jeishman's mixture, staininj; a diffuse pale 

 blue colour with no evidence of nucleus or flagclluni. 



As mentioned on the |)re.vious pat^e, subculture into Novy and MacNeal's blood agar 

 was successful from a thirty-days' gi'owth in the same medium. No forms were recognised 

 in tlie subculture until about the fifteenth day, wlien young trypanosomes, long, thin, and 

 of uniform thickness were seen, some possessing a terminal flagelluin in active motion but 

 not communicating the characteristic undulatory waves to the body, which never altered its 

 regular outline. Typical rosette forms were also very numerous, the numbers composing 

 wiiich ranged from seven up to sixty. Some clumps consisted of dividing spherical and 

 irregular fornis (Plate Jf., fig. '2), while the larger masses comprised forms from small 

 round types in the centre to almost fully-developed trypanosomes radially disposed at the 

 periphery. 



The blepharoplast and nucleus sliowed uj) ))ionouncedly in the stained films, and the 

 protoplasm appeared vacuolated and granular in the young spherical forms, some of which 

 were fused together with dividing blepharoplast and nucleus indiscriminately placed. In 

 the more fully developed trypanosomes, short innnature flagella were seen attached to their 

 anterior ends, the blepharoplast in many cases being likewise situated anteriorly, thus 

 presenting figures identical to the herpetomonad type of ))arasite (Plate TI., fig. 3). 



This strain of T. hnicei (pecandi) is being still further successfully subcultured without 

 difficulty, tlie forms most numerous in each succeeding subculture being those elongated 

 trypanosomes with the terminal flagella which have been most in evidence since the second 

 subculture. 



The virulence of a twenty-two days' culture was tested on a gerbil. but the animal 

 never became infected. 



7iV(rt.a.yfcj. --Although the behaviour of this sti-ain in culture is much like tluit of T. hnicei 

 in some respects, yet, from the numerous cultures made, one cannot say that it 

 only grows exceptional I y on culture media, upon which fact Novy and MacNeal lay 

 stress. Primary cultivation proved comparatively easy in the sense that the trypanosomes 

 maintained their motility and numbers moderately well in the original cultures, and this 

 perhaps more so in Nicolle's medium provided no bacillary contamination ensued after 

 repeated examination. It is true, however, that they did not nniltiply. Like 7'. bnirei 

 it certainly does grow very readily after tlie first subculture has been establislii'd and. in 

 subsequent cultures, the trypanosomes multiply on an extensive scale. 



T. KVANsi (Camkl Rtuainj 



Kejieated attempts were nuide to cultivate this trypauosome from gerbil's blood in the 

 above-n)entioned media but with no success save in so far as the parasites were evident 

 and remained motile up to about eight days, after wliicli no forms could be recognised 

 either in hanging drop or stained films. A few sub-inoculations were made, but none of 

 them revealed trypanosdiius at anv period, tlie media remaining (piite sterile for many 

 weeks afterwards. 



Even after 24 hours' incubation the cultures invariably showed a decided decrease 

 III the number of trypanosomes, although those surviving were very actively motile. 

 The formation of clumps was not marked at any period. In the stained preparations 

 all the trypanosomes present appeared much thinner and decidedly degenerated, with 



