162 



Dr. H. L. Duke. 



[Feb. 26, 



" This objection, formidable as it is on paper, is not so when the local 

 conditions are thoroughly appreciated. In the first place, that part of the 

 coast line where is the little promontory on which my camp has been since 

 March is not sufficiently shaded for Glossinae, which are only present in very 

 small quantity. Moreover, the whole locality round the camp has been very 

 completely cleared, and the edge of the jungle at the base of the promontory, 

 in which there are few flies, is some 50 yards away from the nearest hut. 

 and 100 yards at least from the monkey's quarters. 



"Also, if an occasional fly should accompany the canoe back from that 

 part of the shore where flies are very numerous (nearly two miles away to 

 the south-west) it would not be carried on to the monkey's quarters, but 

 would be intercepted by the boys' huts. As a matter of fact it is an 

 exceptional occurrence to see any Glossinse in the cleared area, and those 

 that are occasionally seen are probably the bred flies which have escaped 

 during manipulations, and these very quickly leave the locality. 



" It might be suggested that one of these may have bitten an infected 

 canoeman or fly- boy, and, subsequently, the experimental monkey ; but 

 I think it must be an exceptional occurrence for a monkey to be bitten by 

 a glossina. A tame monkey which has been with me on the island since 

 April, and has never lecome infected, is immediately aroused to alertness, even 

 when half asleep, by the buzz of a glossina, and when one of my bred flies 

 accidentally escapes the monkey is all eagerness to catch it, whereas an 

 ordinary fly attracts little attention. 



" Moreover, I have no reason to suppose that any of the natives with me 

 on the island are potential sources of T. gavibiense, and blood from all the fly- 

 boys (who are most exposed to infection) has been injected into a monkey 

 with negative result. 



" (Signed) G. D. H. Carpenter, 



"Damba Island, November, 1911." 



