28 Sir D. Bruce and others. G. brevipalpis as a 



trypanosome causing disease in man in Nyasaland in G. morsiians* or with 

 the same forms of T. brucei, Zululand, 1913,f it will be apparent that in all 

 probability this is a true development of this trypanosome in G. brevipalpis. 

 It is true wild flies are being dealt with, but in this district it is only 

 trypanosomes of this type which invade the salivary glands, so that 

 T. pecorum, T. simiw, and T. caprce are excluded. It is very unlikely 

 that T. grayi invades the salivary glands. 



Conclusion. 



G. brevipalpis is capable of acting as a carrier of T. brucei vel rhodesiense, 

 the trypanosome causing disease in man in Nyasaland. 



2. The Development ofT. brucei, Zululand, 1913, in G-. brevipalpis. 



(a) Feeding Wild G. brevipalpis first on Animals infected with T. brucei, 

 Zululand, 1913, 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 VI. 



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 12 ... 



21.30 



80 





10 



1 





Julv 1 ... 



2250 



60 



+ 



2 







51 



„ 17 ... 



2299 



60 















(b) Details of the Three Experiments. 



Table VII. 



Expt. 



Day of 

 expt. 



Procedure. 



Eemarks. 



2130 



1-2 

 3 



4^35 



Flies fed on infected Monkey 1970. 

 Starved. 



Fed on clean Dog 2142. 



80 flies used ; 1 found infected ; 

 only 10 dissected. 



2250 



1-4 

 5-6 

 7-60 



Flies fed on infected Dog 2240. 

 Starved. 



Fed on clean Dog 2276. 



60 flies used ; only 2 dissected, 

 both negative. Dog 2276 showed 

 trypanosomes on the 58th day. 



2299 



1-10 

 11 

 12-61 



Flies fed on infected Dog 2254. 

 Starved. 



Fed on clean Dog 2314. 



60 flies used ; none dissected. 



* ' Eoy. Soc. Proc.,' B, vol. 87, p. 516 (1914). 

 t Ibid., B, vol, 87, p. 493 (1914). 



