Carrier of Trypanosome Disease in Nyasaland. 29 



Two hundred wild G. brevipalpis were used in three experiments — one 

 positive, two negative. Only twelve flies were dissected, one of which was 

 found to contain in the intestine long, ribbon-like trypanosomes of apparently 

 a pathogenic type, but it was not possible to place it. It is to be regretted 

 that all the flies had not been dissected as was the rule in these transmission 

 experiments. 



Dog 2276 became infected 58 days after the flies had fed on the infected 

 animal. This would point to the development of T. brucei, Zululand, in the 

 flies. If there had been a fly in the cage naturally infected with the Nyasa- 

 land strain, then the animal fed upon ought to have shown trypanosomes in 

 its blood earlier than 58 days. It may therefore be held as highly probable 

 that Dog 2276 was infected by a G. brevipalpis in which a development of 

 T. brucei, Zululand, 1913, had taken place. 



Conclusion. 



G. brevipalpis is capable of acting as a carrier of T. brucei, Zululand, 1913. 

 3. The Development of T. pecorum in G. brevipalpis. 



(a) Feeding Wild G. brevipalpis first on Animals infected with T. pecorum and 

 then on Healthy Animals, to ascertain if this Species of Trypanosome passes 

 through a Cycle of Development in this Species of Tsetse Fly. 



Table VIII. 



Date. 



Expt. 



No. 

 of flies 

 used. 



Expt. 

 positive or 

 negative. 



No. of flies 

 dissected. 



No. of 

 infected flies 

 found. 



No. of days 

 before flies 

 became infective. 



1912. 

 May 28 

 June 2 



2190 

 2207 



80 



50 



+ 



17 

 16 



6 

 



29 



One hundred and thirty wild G. brevipalpis were used in two experiments — 

 one positive, one negative. Only 33 flies were dissected ; six found infected. 



(b) Details of the Two Experiments. 



Table IX. 



Expt. 



Day of 

 expt. 



Procedure. 



Remarks. 



2190 



1-3 

 4-5 

 6-36 



Flies fad on infected Goat 2186. 

 Starved. 



Fed on clean Goat 2202. 



SO flies used ; 6 infected flies found ; 

 only 17 dissected. Goat 2202 showed 

 trypanosomes on the 36th day. 



2207 



■ 



1-6 

 7 

 8-46 



Flies fed on infected Goat 2126. 

 Starved. 



Fed on clean Goat 2210. 



50 flies used ; only L6 flies dissected ; 

 all negative. 



