22 Dr. H. L. Duke. Experiments with [Sept. 28, 



Expt. 383. — Positive Box of G. palpalis. 



Date. 



Procedure. 



Eemarks. 



Oct. 24—25 



„ 26 



„ 27—28 



„ 29 



„ 30 



Fed on Monkey 487 24—48 hours after 

 the administration of 01 grm. arsenic 

 per kilogramme. 



Starved. 



Fed on Monkey 493 24— 48 hours after 



arsenic 01 grm. per kilo. 

 Starved. 



26 flies die ; nil. 



Monkey became infected. 1 fly 



dies ; nil. 

 1 fly dies ; nil. 

 + Flies Nos. 1 and 2 found. 



„ 31— Nov. 2... 

 Nov. 3 





» 4 





Description of the two positive flies : — 



Fly 1. Gut and proventriculus : Devoid of flagellates, alive or dead. 



Salivary gland : + + + , with normal active flagellates. 

 Fly 2. Gut : + + , no alteration in form observable. 



Foregut: + , no alteration in form observable. 

 Proventrimlns : Nil. 

 Salivary gland : + + + , normal. 

 In this experiment the flies were afforded an opportunity of a second feed 

 of arsenic blood. In spite of this the salivary flagellates — the infecting form — 

 were, it appears, unaffected. Apparently fly No. 2 illustrates re-infection of 

 the gut from the salivary gland, as it is very improbable that any of the 

 original gut flagellates would survive the double feeding on arsenic blood. 

 Note the mortality after the arsenic feeds. 



Expt. 358.— Positive Box of G. palpalis. 



Date. 



Procedure. 



Remarks. 



Oct. 10—11 ... 



,, 12 



„ 13 



Fed on Monkey 438 24—48 hours after 

 administration of arsenphenylglycin, 

 - 1 grm. per kilogramme. 



Starved. 



+ Flies Nos. 1, 2, 3, 4 found. 







Description of the four positive flies : — 



Ely 1. Gut (containing no blood) : + + + active, normal. 



Proventriculus : + , normal. 



Salivary glands : + + + , active and normal. 

 This fly showed no sign of blood in its gut, and therefore presumably did 

 not feed on Monkey 438. 



