THE ANIMAL KINGDOM. ]()7 



OYilj to a short distance from them; it entraps its victims 

 as they make the passage, and darts upon them with the 

 speed of an arroAV. Dr. Livingstone says that at the time 

 he travelled in this region, these flies sometimes buzzed 

 round his head and those of his fellow-travellers as thick 

 as a swarm of bees. They were often stung all over, as 

 were also their asses, but Avithout either themselves or 

 their beasts of burden experiencing any troublesome re- 

 sult. The sting of this blood-sucker being fatal to our 

 domestic animals, the ox, horse, sheep, and dog, in the 

 countries it devastates, the goat and ass make up the sum 

 total of agricultural cattle. 



The Aictims knoAV their executioner; and Avhen the 

 hum of one of these flies rings in the ears of the cattle 

 they fly, struck Avith fright, in every direction. 



Such guests as these not only paralyze agricultm-e, but 

 place a limit to the explorations of man. Deprived of 

 his beasts of burden and his food, he cannot traA^erse the 

 domain of the redoubtable fly; and if by chance he can 

 brave the danger, it is only by taking adA^antage of the 

 time of its repose. Whenever one is obliged to send 

 flocks of sheep or herds of cattle across countries infested 

 by the tsetse, the natives choose cold moonlight nights, 

 knowing that at such times the insect, sleepy and stupi- 

 fied, Avill not sting the cattle. 



The domestic fly, inoff"ensive in our dAvellings, torments 

 Avithout ceasing those who travel in hot countries. There 

 it is dreaded more than the hyaena and jackal, and Ave 

 can only guard against it l)y having a croAvd of slaves 

 about us. In some of the villages of Upper Egypt I 

 have sometimes seen in their mothers' arms, children at 

 the breast, AA'hose faces Avere iuA'aded 1)y such compact 

 legions of flies that they looked like craAvling black 



