1912.] Arsenphenylglycin and T. gambiense in G. palpalis. 25 



Expt. 712. 



Date. 



Day of 

 expt. 



Procedure. 



Remarks. 



Apr. 15 



„ 16—17 



„ 18 



„ 19—20 



» 21 



„ 22— May 20 

 May 21—22 



1—2 

 3 



4—5 



6 



7-35 

 36—37 



Fed on Monkey 708 48 hours after the 

 administration of arsenic, O'l grm. per 

 kilogramme. 



Fed on Monkey 711 24 — 48 hours after 

 the administration of arsenphenyl- 

 glycin O'l grm. per kilogramme. 



Starved. 



Fed on Monkey 597, which shows T. 



gambiense + . 

 Starved. 

 Fed on cock. 



3 + flies found out 

 of 112 dissected 

 = 2'6 per cent. 



Expt, 713 (control). 



Date. 



Day of 

 expt. 



Procedure. 



Remarks. 



Apr. 15—17 



„ 18 



„ 19-20 



„ 21 



„ 22— May 20 

 May 21— 22 



1—2 

 3 



4—5 

 6 



7—35 

 36—37 



Fed on normal monkey. 

 Starved. 



Fed on Monkey 597 (T. gambiense + ). 



Starved. 



Fed on cock. 



8 + flies found out 

 of 69 dissected 

 = 115 per cent. 



From these two experiments, as far as any conclusion can be drawn from 

 such limited evidence, it would appear that the initial arsenic feeds influence 

 unfavourably the subsequent development of the flagellates in the fly. 



III. Does Feeding on Arsenic-containing Blood, immediately after the Infecting 

 Feeds, prevent the Subsequent Development of Flagellates in the Fly, or does 

 it result in the Production of an Arsenic-fast Strain ? 



Expt, 416. 



Date. Day of expt. 



Procedure. 



Result. 



Sept. 30— Oct. 1 

 Oct. 2 



1 



2 

 3 



4—51 

 52—53 



Fed on Monkey 199 



(T. gambiense + ). 

 Fed on cock. 

 Starved. 



Fed on Monkey 426... 

 Starved and dissected 



Monkey 426 received - 1 grm. per 

 kilogramme arsenphenylglycin on 

 Oct. 3. It eventually became in- 

 fected. 



1 + fly out of 82 dissected = 1 "2 

 per cent. 



,, 3 



„ 4— Nov. 20... 

 Nov. 21—22 



