376 Col. Sir D. Bruce and others. [Apr. 18. 



Experiment 1566. 



Date. 



Day 

 of experi- 

 ment. 



Procedure. 



Eesult. 



Remarks. 



Positive. 



Negative. 



1909. 

 Aug. 29— 



Sept. 1 

 Sept. 2—3 

 „ 4- 

 Oct. 19 

 Oct. 20 



1—3 



4-5 

 6—51 



52 



Flies fed daily on in- 

 fected ox 



Flies starred. 



Flies fed on healthy 

 monkey, 1566 



Flies starved. 



+ 





35 flies used. 



Oct. 21, 20 remain- 

 ing flies killed and 

 dissected ; 9 found 

 infected. 



Remarks. — Thirty-five laboratory-bred flies were fed daily for four days on an ox 

 infected with Trypanosoma gambiense. Fifty-three days after their first feed the flies 

 became infective. Nine of the 20 remaining flies, when dissected, showed infection with 

 flagellates : three of these had infection of the proboscis. The contents of the alimentary 

 canal of one infected fly injected into a monkey and goat gave negative results, as also did 

 the probosces of two infected flies when injected into a goat. 



Experiment 1602. 





Day 





Result. 





Date. 



of experi- 



Pi-ocedure. 







Remarks. 





ment. 





Positive.. 



Negative. 





1909. 













Sept. 1—4 



1—3 



Flies fed on infected 







50 flies used. 





ox daily 









5—6 



4—5 



Flics starved. 









7—14 



6—13 



Flies fed on healthy 













monkey, 1()20 









„ 15—20 



14—19 



Flies fed alternately, 













daily, on healthy 













monkey, 1620, and 













goat, 1690 







Sept. 29, 32 remain- 



„ 21-29 



20—28 



Flics fed alteriiiitcly, 



1703 



1690 



ing flics killed by 







daily, on liciiltliy 



+ 





accident and dis- 







monkey, 1703, and 







Bccted ; 5 found in- 







goat, 1690 







fected. 



Remarlcs. — Fifty laboratory-bred flies were fed daily for four days on an infected ox, as 

 in the previous experiment. From the 15th to the 28th day the flies were fed alter- 

 nately on a monkey and goat. Twenty-seven days after tlieir first feed the flies infected 

 monkey 1703 with Sleeping Sicknes.s. Five of the 32 remaining flies showed infection 

 with flagellates, and one of these injected into a monkey gave rise to Sleeping Sickness. 



