Carrier of Trypanosome Disease in Nyasaland. 25 



Table III. 



J^ate. 



-tixpt. 



^ 0. 



or mes 

 used. 



x.xpr. 

 positive or 

 negative. 



Ko. of flies 

 dissected. 



Jfo. of 

 found. 



IJ . (J I KXa. > 5 

 rw>mTP nip; 



became infective. 



1913. 















Mar. 6 ... 



1986 



2 





1 









„ 26 ... 



2062 



10 





6 









June 2 ... 



2201 



70 





8 



2 





» 9 ... 



2213 



60 





19 



2 





„ 21 ... 



2232 



50 





18 



4 





July 23 ... 



2310 



40 





1 









(b) Details of the Six Negative Experiments. 



Table IV. 



Expt. 



Day of 

 expt. 



Procedure. 



Remarks. 



1986 



1 



Flies ted on mieeted G-umea- 

 pig 1658. 



Only 2 flies used ; one escaped and the 

 other died on the 15th day of the ex- 





2-4 



Starved. 



periment ; on dissection it was found 





5-15 



Fed on clean Guinea-pig 1907. 



negative. 



2062 



1-4 



Elies fed on infected Monkev 



10 flies used. 6 were dissected : all 





5 



970. 

 Starved. 



negative. 





6-28 



Eed on clean Dog 2041. 





2201 



1-6 



Flies fed on infected Monkev 

 2156. 



70 flies used. Only 8 were dissected ; 

 2 found infected, one with T. grayi, the 





7 

 8-33 



Starved. 



Fed on clean Dog 2211. 



other with a pathogenic type of trypano- 

 some. 



2213 



1-12 



13-14 

 15-44 



Flies fed on infected Monkev 



2151. 

 Starved. 



Fed on clean Dog 2237. 



60 flies used. 2 found infected. Only 

 19 dissected. 



2232 



1-6 



Flies fed on infected Monkev 

 2152. 



50 flies used : 4 found infected. 18 flies 

 dissected. The 4 infected flies showed 





7-9 



Starved. 



infection of the gut alone 





10-42 



Fed on clean Dog 2244. 



2310 



1-3 



Flies fed on infected Monkev 



40 flies used. Only one fly dissected ; 





4-5 



1792. 

 Starved. 



negative. 





6-39 



Fed on clean Dog 2315. 





{c) Result of the Dissection of the Infected Flies. 



As will be seen from Table III, eight infected flies were found among the 

 G. hrevipalpis which had fed on animals infected with the trypanosome 

 causing disease in man in Xyasaland. The following Table gives the result 

 •of the dissection of these eight flies : — 



