151 



importance than those of Siomoxys ; yet the role of tlie latter 

 cannot be overlooked." 



As bearing on tlie question of tlie role of Stornoxys as a simple 

 carrier, it may be mentioned that in Uganda Greig and Nabarro 

 never succeeded in conveying trypanosomes from infected to healthy 

 animals by means of Stornoxys, when the intervals were as long as 

 six or twenty-four hours* ; and that Greig and Gray similarly 

 failed to convey " Jinja cattle " and mule trypanosomes by the 

 bites of Stornoxys after intervals of eight and twenty-four hours, f 

 As a result of their experiments, Greig and Gray (who appear to 

 ignore cases in which a fly bites a healthy animal immediately after 

 sucking blood from an infected one) write : — '* It may be, further, 

 considered proved that Stomoxys cannot convey these trypanosomes 

 from the sick to the healthy animals. This is a matter of great 

 practical importance also, because these flies abound in Uganda. "J 

 An examination of specimens forwarded to the Museum shows that, 

 in these experiments in Uganda, both Stomoxys calcitrans, L., and 

 *S^. nigra, Macq., were employed. 



Experiments on direct transmission of Trypanosoma gambiense 

 by means of any species of Stomoxys do not yet appear to have been 

 made, but the fate of this parasite when ingested with blood by 

 S. calcitrans or S. nigra would seem to be disappearance (digestion) 

 within two days. According to Dutton, Todd, and Hannington § : — 

 " In the Gambia, trypanosomes, identical with those ingested, were 

 found unchanged in the gut of Stomoxys\\ up to twenty hours after 

 they had fed heavdly on a horse infected with Trypanosonui gambiense. 

 Longitudinal divisional forms were seen." In Uganda, however, 

 Minchin found that when Stomoxys\\ and Mosquitoes were fed upon 

 animals infected with Trypanosoma gambiense, the trypanosomes 

 ingested by the flies " went through the same changes of form and 

 structure as in Glossina palpalis,^' but that, in Stomoxys, " no 



* Cf. Reports of the Sleeping Sickness Commission, No. 5, p. 40 (July, 1905). 



t Ibid., No. VI., pp. 203-208. 



X Ibid., p. 209. 



§ Annals of Tropical Medicine and Parasitology, Series T.M., V'ol. I., No, 2, p, 221 

 (June 15, 1907). 



II Either Stomoxys calcitrans, L., or S. nigra, Macq., or both. — E.E.A. 



