1910.] The Development of Trypanosomes in Tsetse Flies. 387 



Experiment 1035. 



Date. 



Day 

 of experi- 

 ment. 



Procedure. 



Re.sult. 



Remarks. 



Positive. 



Negative. 



1909. 

 June 21—23 



„ 24—25 

 „ 26— 

 Julv 1 

 July 2-^ 

 5— 

 Aug. 2 

 Aug. 3—24 



1—2 



3-4 

 5—10 



11-13 

 14—42 



43—64 



Flies fed on infected 



goat. 

 Plies starved. 

 Flies fed on healthy 



goat, 1171 

 Flies starved. 

 Flies fed on healthy 



goats, 1257 and 1258. 

 Flies fed on goat 1258 



+ 





120 flies used. 



• 



Aug. 3, goat 1257 

 died ; negative. 



Aug. 25, 9 remain- 

 ing flies dissected ; 

 negative. 



Remarks. — One hundred and twenty wild flies were fed for three days on an infected 

 goat. Five days after their first feed they infected a healthy goat, or, at least, trypano- 

 .somes resembling Tri/panosoma nanum appeared in the blood. They failed to infect 

 other healthy goats, although they were fed up to the 64th day after their first infected 

 feed. Nine remaining flies dissected on the 65th day were negative for flagellates. 



H. The Drvclopment o/ Trypanosoma nanum in, Laboratory- Bred Glossina 



palpalis. 



Table XII. — The Development of Trypanosoma nanum in Laboratory-Bred 



Glossina palpalis. 



Experiment. 



No. of flies. 



No. of 

 days fed on. 



No. of days before 

 flies became infective. 



No. of days flies 

 remained infective. 



1738 



100 



3 







Only one experiment was carried out with laboratory-bred flies. The 

 result was negative. 



Experiment 1738. 



Hemarkt. — One hundred laboratory-bred flies were fed for three days on an ox whose 

 blood contained Trypanosoma nanum, and then on a healthy goat for 40 days. This goat 

 remained healthy, and all the flies when dissected were found free from flagellates. 



A few experiments were made by the Commission on the development of 

 Trypanosoma brucei and Trypamsoma cazalhoui in the Sleeping Sickness 

 tsetse fly, Glossina palpalis, but they came to nothing. 



VOL. LXXXII. — B. 2 H 



