1912.] Reservoir for Trypanosoma gambiense. 



309 



Two tubes A and B were prepared, each containing ^ vol. serum and 

 § vol. citrated T. gambiense-blood. Tube A contained serum of Eeedbuck 

 2359 ; tube B serum of a bushbuck which had never been infected with 

 T. gambiense. The tubes were placed for four hours in incubator at 28° C. 

 The contents were examined at intervals during this time, but no difference 

 was observed in the motility of the trypanosomes, and no agglutination was 

 seen in either tube. 



(2) Has serum of Eeedbuck 2359 any protective action against 

 T. gambiense ? 



(a) On June 15, 1911, a white rat received 15 iri serum of reedbuck, 

 and on June 16, 1911, 24 hours after, was injected with a small dose of 

 T. gambiense. The rat died in 25 days. 



(b) In two tubes A and B were placed respectively ^ vol. of serum of 

 reedbuck and § vol. of citrated T. gambiense-blood, and ^ vol. serum of 

 normal bushbuck and § vol. of citrated T. gambiense-blood. The tubes were 

 kept at room temperature in the dark. The contents of the tubes were 

 examined at intervals of 3, 5^, and 6-| hours, without any differences being 

 noted ; 6| hours after the commencement of the experiment, 6 v\_ of each 

 tube-contents was inoculated into white rats C and D. These rats died in 

 23 and 21 days respectively. 



The T. gambiense employed in the above experiments was a strain derived 

 from wild Lake-shore flies. It is to be regretted that no control injection of 

 trypanosomes alone was performed, owing to scarcity of rats and my failure 

 at the time to realise the importance of the point. 



It will be noticed that the disease in both cases was extraordinarily rapid. 

 Whether this was due to the trypanosome strain, or to the antelope serum, 

 or to both these factors, cannot at present be decided. The monkey from 

 which the trypanosome was taken was killed two months after the infection. 

 Iu a subsequent experiment, in which a white rat was injected with another 

 strain of Lake-shore trypanosomes derived from fly, the disease lasted 

 54 days. The various T. gambiense strains at Mpumu all give rise to a 

 fairly protracted disease in rats. 



The above facts warrant an enquiry as to the identity of the trypanosomes 

 obtained in monkeys by feeding wild Lake-shore G. palpalis upon these 

 animals. The trypanosomes so obtained have always been described by 

 Bruce as T. gambiense, though I am unaware of the nature of the evidence 

 adduced in support of this assertion. It is, of course, extremely probable, 

 considering the recent epidemic along the Lake-shore and the nature of local 

 cattle diseases, that these trypanosomes found in wild flies and pathogenic to 

 monkeys are T. gambiense. Nevertheless, the question cannot be summarily 



