386 



Col. Sir D. Bruce and others. 



[Apr. 18, 



Table X. — Number of Flies found Infected with Trypanosomes in the 

 Experiments with Laboratory-Bred Flies and Trypanosoma vivax. 



Experiment. 



No. of 

 flies used. 



Experiment, 

 positive or 

 negative. 



No. of infected 

 flies fovmd. 



Result 

 of injection of 

 infected flies. 



Remarks. 



1591 



50 



+ 



3 



Not injected 



Probosces infected. 



1698 



68 



+ 



5 





1700 



60 



+ 



22 



+ 





In these experiments 178 flies were used, and of these 30, or 17 per cent., 

 became infected. A curious fact is that in all the 30 flies, with the 

 exception of one, the infection was confined to the proboscis. There was 

 a feeling in the minds of the members of the Commission that this growth 

 of flagellates in the proboscis was something quite characteristic of Trypano- 

 soma vivax. Only on one occasion was this development of trypanosomes in 

 the proboscis seen after feeding laboratory-bred flies on blood which was 

 known to contain nothing but Trypanosoma gambiense. 



G. The Development of Trypanosoma nanum in Lalce-shore Glossina palpalis. 



Table XI. — The Development of Trypanosoma nanum in Lake-shore 



Glossina palpalis. 



Experiment. 



No. of flies. 



No. of 

 dajs fed on. 



No. of days before 

 Hies became infective. 



No. of days flies 

 remained infective. 



1035 



120 



3 



3 



3 



Only one experiment was carried out with Trypanosoma nanum and Lake- 

 shore GlossivM, palpalis. It is unsatisfactory, as trypanosomes appeared in 

 the first healthy goat a few days after the fly had fed on tlie infected animal. 

 None of the flics which were dissected showed any flagellates in their 

 alimentary canal. 



