210 MR. F. J. JACKSON ON TSETSE. 



from the rays of the sun — such as under the brim of the 

 hat, behind the ear, neck, and under the throat if not 

 protected by a beard. If allowed to suck itself full, its 

 body becomes so distended that it has the appearance 

 of a small unripe purple grape, and it is unable to fly more 

 than a few yards before settling. Its proboscis, which 

 is very slightly curved downwards, is attached to the 

 head horizontally, and is protected by a sheath divided 

 longitudinally. When it bites, the proboscis is vertically 

 lowered, whilst the double sheath is retained in its hori- 

 zontal position. This fly is perfectly harmless to human 

 beings, but its efiect on domestic animals is of the most 

 disastrous nature — in fact, as far as my knowledge goes, 

 all domestic animals, with the exception of goats, and 

 perhaps of the grey donkey, when struck by this fly are 

 bound, sooner or later, to die. I do not believe that 

 donkeys are impervious to its bite, and I think that the 

 wasting disease which kills off so many of them comes from 

 the efiect of being bitten by these flies. I have seen a 

 bullock cut up, after dying from these wasting symptoms, 

 which I knew to have been bitten by the Tsetse ; the 

 whole of the juices of the body were turned into greenish- 

 yellow slime. I sent home a number of these Tsetse 

 which I caught myself, and which were certified as the 

 genuine fly by the authorities at the British Museum. 

 . . . The route which appears to me to be far more 

 practicable for transport by means of animals is that by 

 Taveta, which lies at the foot of Mount Kilima-Njai'o, and 

 from there runs almost dii'ect northwards to Machakos. 

 Throughout the whole of that way both good fodder and 

 water are plentiful ; there is no thick bush, and there are 

 no Tsetse. The fact of the immense herds of native cattle 

 which the Masai have roaming over all these plains is 

 sufficient to prove this ; if these herds are able to live, the 

 Tsetse cannot be there. . . . The depot at Taveta would 

 have to be built outside the forest, on the banks of the 

 River Lumi, as there is a fly, not the Tsetse, but exactly 

 like a house-fly with a long proboscis, that is very plentiful 

 inside, and worries beasts to such an extent that they are 

 unable to eat, and die." 



[The fly alluded to in this last paragraph is obviously 

 a species of Stomoxys, and since Tryjpanosoma brucei was 



