﻿AND HABITS OF GLOSSINA FUSCIPES IN UGANDA. 59 



The fact that fuscipes and not palpalis would seem to be the intermediary host 

 for Trypanosoma gambiense in Uganda, while of interest, is of no importance in 

 itself ; but it may prove a factor in solving the question of the difference in 

 virulence in trypanosomiasis as seen on the West Coast and in Uganda, and also 

 the lessened reaction to treatment of the Uganda type. For if G. fuscipes should 

 prove a more favourable intermediate host the organism would very probably 

 have its virulence enhanced in the passage. A recent report from Togoland 

 gives the percentage of apparent cures as 67 per cent." I do not know the per- 

 centage for Uganda but it would appear to be almost negligible. 



In view of the noticeable difference in the habits of the Central Africa fuscipes 

 and the West African palpalis, the strongly contrasted sites chosen for the 

 deposition of larvae and the difference, though less in degree, in the external 

 characters, it seems a matter of wonder that the specific, or possibly subspecific, 

 distinction should not have been established much earlier. 



Nimule, Nile Province, 7th November, 1911. 



[So far as the present evidence goes, Dr. McConnell's suggestion that all 

 Uganda specimens of G. palpalis are probably referable to the form fuscipes, 

 Newst., seems likely to be justified. He has sent mounted examples of his 

 dissections to the Entomological Research Committee, and there can be no doubt 

 as to the correctness of his determinations. Moreover, Dr. J. J. Simpson, while 

 in England, made preparations of the male genitalia of other Uganda specimens, 

 all of which are clearly referable to the same form. On the other hand, it must 

 be pointed out that the essential external characters given by Prof. Newstead 

 for G. fuscipes and based on his single (apparently dwarfed) specimen, do not 

 appear to be normal ; and in spite of careful examination by Mr. E. E. Austen, 

 Dr. Simpson and the writer, it has not been possible to find any constant, reliable 

 external character by which G. juscipes can be distinguished from typical 

 G. palpalis. Mr. Austen has recently dissected out the genitalia of some 

 dark forms of palpalis from the Congo, and these agree essentially with those 

 of the Uganda fuscipes. In the circumstances it seems advisable to treat 

 G. fuscipes merely as a local form of the Western G. palpalis. It is very 

 improbable that the greater virulence of sleeping sickness in Uganda is really 

 connected with the small sub-specific difference in the Glossina which carries it. 

 The more probable explanation is that it is due to the fact that the disease has 

 been only recently introduced into Uganda ; whereas there is now evidence that 

 sleeping sickness has long been endemic in parts of West Africa, so that we 

 should expect the production of a fairly high degree of immunity in the natives 

 by the simple process of selection. — Ed.] 



# [This estimate has clearly no real value, for Zupitza records (cf. SI. Sick. Bull. 1909, p. 400) 

 that in the treatment camps in Togo patients who have remained well for six months after 

 treatment are regarded as cured ; a method which is condemned by Dr. Bagshawe as " unjustifi- 

 able and possibly mischievous." — Ed.] 



