341 
v\ork may regain i. nanum in the Sudan, when its position may be 
made more clear; until that time its specificity must remain 
questionable, though we incline to consider it as distinct from 
J.dmorpkon,, and, therefore, to have no relation to the trypanosome 
of Xorth Western Rhodesia which we have associated with that 
species.* Further, its small dimensions preclude the possibility of its 
connection with either I . '. n ax or I ■ cazalboui. 
In luly, 1906, Laveran'" announced his belief that the trypanosome 
of‘La Soumaya' was a new species, to which he gave the name 
T. cazalboui. Up to this lime the impression had been created by 
various writers that the causal agent of Ua Soumaya was T. evans^ 
and, indeed, such statements had been made. Uaveran and Mesnil 
say ‘ ils ont la plus grande resemblance avec le trypanosome de a 
Mbori,’ and they proceed to tjuote Cazalbou’s animal inoculations 
which resulted in the death of grey rats, mice and Sudanese dogs. n 
a later paper, published in May, 1907, Laveran^ advances sue 1 
additional evidence as to make the species incontesti e. y 
morphology, animal reactions and cross-inoculations, 2. caza out 
clearly separated from the n-ami and dimorphon groups, and trom 
r. to which it is only related by the similarity of animal 
reactions. On all grounds it is a ‘ good species, and one w ic c 
be detected and classified in the field with comparatively Utt ® ^ 
The same can hardly be said of I- vivax, as we yet kno , 
organism described by Ziemann in 1905, a year before 2 . caza ou 
was created, and given a specific name mainly on accoun o 
rapidity of motion in cover-glass preparations. The morp o ogy 
this organism is in dispute : Ziemann'^ distinguishes it rom ■ ^ > 
though Laveran'^ was unable to note any difference from " 
in the film he examined; and Schilling'* contends that it is 
slightly more rapid form of T. brucci. This opinion is n*^ 
by Uhe, who writes'^ ‘ Ich selbst finde in einem mir 
' Originalpraparate die unter sich durchaus 
Tiypanosumen kleiner wie ■ ' ' ' , . 
■ausgebildeter undulierender Membran, wenig her^^o^refend ^ 
h i 3h<5 N ot. 3) tias apparently 
•\Venyon (Report of the Wellcome 'voanosomes we have isolated 
recovered T. Kanum. We consider that one of 1 "® . -,„selv allied to this 
Iw cam., ahaep and goal, in North Kaatern Khodesm .s closely 
rpecies. (April islh, 1909.1 
