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T. dimorphon brought about a febrile reaction and the 
appearance of this organism in the blood. 
4. The post-mortem appearances; Splenic enlargement was 
not noted in the three cases upon which autopsies were 
possible, whereas in T. dimorphon infection it was a 
common feature. 
Sander and Hennig ® state that according to Ziemann T. vh ax 
occurs spontaneously in cattle, sheep and goats ; the incubation period 
is 5'8 days; and on post-mortem, enlargement of the liver or spleen 
is seen. Experimentally, grey rats died in 8-11 days; in donkeys 
the disease is chronic, and in a German dog the reaction was 
apparently doubtful. A negative result was obtained in a white rat. 
In Rhodesia white rats and native dogs were negative; the one 
donkey inoculated did not show organisms, but it has not been 
examined or reported on for three months and we are ignorant of its 
present state. A point of difference we note is the enlargement of 
the spleen, but our observations are based on three post-mortems 
only. 
The morphology, as given by Liihe, differs from that of the form 
under discussion in possessing an alveolar protoplasm and a somewhat 
pointed end. These are minor points, negligible so far as the 
morphology of other trypanosomes is concerned, in which similar 
variations are commonly seen. The experimental work on both sides 
is limited, but the animals used are similar, and if Ziemann’s dog was 
negative, and such is a possible interpretation, the results coincide, 
though we were unable to use grey rats and pigs in which Ziemann 
obtained positive reactions. 
We know of no other trypanosome whose activity approaches 
that of this form. On morphological grounds, then, and animal 
reactions this trypanosome coincides more closely to that of Ziemann 
than to any other, and with all reserve, we fee] justified in considering 
the second parasite of Rhodesian cattle as sufficiently closely allied to 
T. vivax, Ziemann, to bear that name until the classification of the 
genus be put on a more satisfactory basis. 
