34 6 
7 . brucei are also less extensive. The posterior end of 
T. brucei is also blunter than that of 7 . evansi. The 
free portion of the flagellum is shorter in 7 . brucei than 
7 . evansi , and the protoplasm of 7 . brucei has more 
numerous and larger granules than that of 7 . evansi. 
The nuclei and the blepharoplasts are morphologically 
indistinguishable. Further, the mean length of 7 . 
brucei is less than that of 7 . evansi , and the width of 
7 . brucei is greater. The distinction between Surra 
and Ngana is, however, best proved by the fact that 
an animal immunized against Ngana is yet susceptible 
to inoculation with Surra. 
Pathology. —The spleen is enlarged and there is 
general glandular enlargement. 
7 ransmission. —Rogers got positive results by 
means of Tabanidae. Stomoxys sp. has been suspected, 
but there are no positive experimental data. 
El Debab (= Surra).—A disease of camels in 
Algeria, is transmitted by Atylotus nemoralis and 
A. tomemtosus. 
Mbori (= Surra).—A disease of Sudan camels, is 
transmitted by 7 abanus ditaeniatus and 7 . biguttatus. 
Aino. —A trypanosomiasis of camels in Somaliland, 
is also possibly Surra. Likewise 7 . vivax affecting 
cattle, sheep and goats in the Cameroons is, according 
to Laveran and Mesnil, Surra. 
Cultivation.— Is even more difficult than in the 
case of 7 . brucei. Novy and McNeal state that Surra 
from the Philippines does not form rosettes in culture 
like 7 . brucei , whereas Laveran and Mesnil with the 
Mauritius Surra obtained them. It is possible, then, 
that these also are varieties. 
4. 7 . equinum. —The cause of Mai de Caderas, a 
disease of horses in Central and South America. 
Symptoms. —(1) Remittent fever ; (2) Progressive 
