408 Col. Sir D. Bruce and others. Hie Development of [July 5, 



monkeys under observation here, sick and healthy. They are all examined 

 twice a week, but during the last eight months not a single case of accidental 

 infection has taken place. 



Details of the Experiment. 

 Experiment 663. 



To ascertain if development of Trypanosoma gambiense takes place in the 

 interior of Glossina palpalis, and if so, how long does the fly remain infective. 



March 5, 1909. — Two batches of Glossina palpalis caught on the Lake 

 shore, consisting of 30 flies in each batch, were fed on monkeys, 

 Experiments 568 and 214, whose blood contained numbers of Trypanosoma 

 gambiense. 



March 6. — The flies again fed as on the 5th, to ensure that as many as 

 possible should get a feed of the infected blood. Nearly all the flies fed on 

 one or other occasion. The flies are kept in a moist atmosphere at 22° C. 



The following table gives the principal details of the experiment : — 



Table II. 



Date. 



Day of 

 experi- 

 ment. 



Procedure. 



Besult. 



Remarks. 



Positive. 



Negative. 



1909. 















Mar. 5 







Flies fed on infected monkey 









6 



1 





» j» >> 









7 



2 





Flies starved 72 hours 









8 



3 













9 



4T) 













10 



5 













11 



6 



> 











12 



7 













13 



8 













14 



9" 













15 



10 













16 



11 





>, 651 









17 



12 













18 



13 J 













19 



14^ 













20 



15 













21 



16 



■ ■ 











22 



17 













23 



18j 













24 



19" 













25 



20 













26 



21 



> 



>j ,» 653 



+ 







27 



22 











28 



23. 













29 



24" 













30 



25 













31 



26 





» 654 



+ 







Apr. 1 



27 













2 



28 J 







1 



