34 



Sir D. Bruce and others. Trypanosorne 



Two hundred and forty flies were used and twenty-four infected flies 

 found — 10 per cent. The first two experiments were carried out at the 

 ordinary temperature of the laboratory ; in the others the flies were kept in 

 the incubator. 



Details of the Five Positive Experiments. 



« 



The following Tables give the principal details in the carrying out of 

 the five positive experiments. They were all carried out with laboratory- 

 bred flies : — 



Table II. 



Expt. 



Day of 

 expt. 



Procedure. 



Eemarks. 



546 



1-3 



4 

 5-62 

 63 

 64-82 



22 flies fed on T. pecorum- 



infeeted dog. 

 Starved. 



Fed on clean Goat 559. 

 Starved. 



Fed on clean Dog 880. 



Goat 559 became infected on the 60th day ; 

 Dog 880 on the 82nd day. All flies dis- 

 sected ; 4 found infected. 



524 



1-5 



6 

 7-44 



20 flies fed on T. pecorum- 



infected rat. 

 Starved. 



Fed on clean Dog 541. 



Trypanosomes first appeared in blood of 

 Dog 541 on the 44th day. All flies dis- 

 sected ; 2 found infected. 



1737 



1-3 



4 

 5-27 



40 flies fed on T. pecorum- 



infected dog. 

 Starved. 



Fed on clean Dog 1750. 



Trypanosomes first appeared in blood of 

 Dog 1750 on the 26th day. All flies dis- 

 sected ; 3 found infected. 



1853 



1-3 



4 

 5-25 



25 flies fed on T. pecorum- 



infected dog. 

 Starved. 



Fed on clean Goat 1903. 



Trypanosomes first appeared in blood of 

 Goat 1903 on the 31st day. 25 flies dis- 

 sected ; 5 found infected. 



1950 



1-8 

 9 



10-29 



33 flies fed on T. pecorum- 



infected goat. 

 Starved. 



Fed on clean Dog 1973. 



Trypanosomes first appeared in blood of 

 Dog 1973 on the 28th day. All flies dis- 

 sected ; 6 found infected. 



It would appear from these five positive experiments that a period of from 

 19 to 53 days may elapse before the cycle of development of Trypanosoma 

 pecorum in G. morsitans is complete and the fly becomes infective. 



Details of the Two Negative Experiments. 



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

 negative experiments : — 



