216 



Sir D. Bruce and others. • Trypanosome 



58 days may elapse before the cycle of development of the Naturally 

 Infected Dog strain is complete in G. morsitans and the fly becomes infective. 



Details of the Mine Negative Experiments. 



The following Table shows the method of procedure in carrying out the 

 nine negative experiments. In each of them laboratory-bred Hies were used. 



Table III. 



Expt. 



Day of expt. 



Procedure. 



Eemarks. 



1257 



1-5 

 6 



7-44 



25 flies fed on infecied Dog 090. 

 Starved. 



Fed on clean Dog 1313. 



All flies dissected ; all 

 negative. 



1499 



1-3 

 4 



5-48 



26 flies fed on infected Eat 1218. 

 Starved. 



Fed on clean Dog 1500. 



All flies dissected ; one 

 found infected. 



1668 



1-3 

 4-5 



6-23 



10 flies fed on infected Monkey 1630. 

 Starved. 



Fed on clean Monkey 1670. 



All flies dissected; all 

 negative. 



1753 



1-3 



4 

 5-40 



50 flies fed on infected Monkey 1534. 

 Starved. 



Fed on clean Monkey 1778. 



18 flies dissected; all 

 negative. 



2018 



1-8 

 9 



10-30 

 31 



32-45 



55 flies fed on infected Eats 1985 and 



2023. 

 Starved. 



Fed on clean Monkey 2056. 

 Starved. 



Fed on clean Dog 2112. 



18 flies dissected ; 2 in- 

 fected. 



2018a 



1-8 



9 



10-35 



40 flies fed on infected Dog 2054. 

 Starved. 



Fed on clean I Jog 2172. 



36 flies dissected; 7 

 found infected. 



2226 



1-6 

 7 



8-37 



40 flies fed on infected Eat 2214. 

 Starved. 



Fed on clean Dog 2233. 



8 flies dissected ; 1 in- 

 fected. 



2303 



1-2 

 3-13 

 14 

 15-44 



40 flies fed on infected Duiker 2059. 

 Fed on infected Eat 2280. 

 Starved. 



Fed on clean Dog 2319. 



29 flies dissected; all 

 negative. 



2433 



1-3 



4 

 5-38 



20 flies fed on infected Eat 2425. 

 Starved. 



Fed on clean Dog 2435. 



15 flies dissected; all 

 negative. 



