Sleeping Sickness in Uganda. 



57 



islanders were highly infected with Sleeping Sickness, this constituted a 

 danger to the healthy natives of the mainland, who had come to the market 

 from outside the Sleeping Sickness area. Steps were at once taken to have 

 the landing thoroughly cleared of undergrowth, witli the result that in a 

 short time the flies disappeared. 



The following experiment shows the result : — 



Experiment 52. — Monkey. 



To ascertain if Glossina i)alpalis caught at Kibanga market-place are capable 

 of giving rise to Sleeping Sickness in a healthy monkey. 



Date. 



No. of flies. 



Trypano- 

 somas. 



Malaria. 



Date. 



No. of flies. 



somes. 



Malaria. 



Put 

 on. 



Fed. 



Put 

 on. 



Fed. 



1908. 









I 



1908. 











Not. 3 











Dec. 6 









+ 



„ 6 









+ 



7 









+ 



. 14 



15 



72 





+ 



„ 15 









+ 



„ 16 



17 



17 





+ 



„ 17 



1 



1 







„ 17 



7 



7 





+ 



„ 18 









+ 



„ 18 



4 



1 





+ 



„ 23 









+ 



„ 19 



7 



4 





+ 



„ 26 









+ 



„ 20 









+ 



>, 30 









+ 



„ 22 



50 



34 





+ 













23 









-r 



1909. 











„ 24 









+ 



Jan. 4 









+ 



„ 25 









+ 



» 9 









+ 



„ 27 









+ 



„ 18 









+ 



„ 29 









+ 



„ 20 









+ 



„ 30 









+ 



„ 26 









-r 



Dec. 2 



10 



7 





+ 



„ 28 











+ 



„ 3 



12 



5 





+ 



Feb. 6 









+ 



„ 4 



5 



3 





+ 



Mar. 1 



1 









+ 



EemarJcs. — The result of this experiment is negative. The number of 

 flies caught is small, and they soon disappeared as the clearing of the place 

 proceeded. 



The other experiments were all made with freshly-caught flies from 

 uninhabited places on tlie Lake-shore. The Lake-shore, as stated above, had 

 been cleared of its inhabitants in December, 1907, and had, therefore, been 

 deserted for nearly a year when these experiments began. It was anticipated 

 that the flies would be found non-infective, as, in the absence of Sleeping 

 Sickness cases, it was difficult to understand where they could obtain the 

 necessary trypanosomes, and at this time the long period of infectivity of the 

 fly was unknown. The following experiments give the result : — 



