6184 



Insects. 



who were provided with three waggons and a large number of trek, or 

 draught oxen, lost, prior to their return to the lake, all their cattle by 

 the bite of the tzetze. Some horses brought with them to further 

 their sport shared a similar fate. 



"The very same year that this disaster happened to the Griquas, a 

 party of Englishmen, amongst whom was my friend Frederic Green, 

 attempted to reach Libebe ; but they had only proceeded seven or 

 eight days journey to the north of the Ngami, when both horses and 

 cattle were bitten by the fly in question, aud the party were in con- 

 sequence compelled to make a hasty retreat. One of the number, I 

 was told, was thus deprived of as many as thirty-six horses, excellent 

 hunters, and all sustained heavy losses in cattle. 



" There are large tribes which cannot keep either cattle or horses 

 because the tzetze abounds in their country. But it is only fatal 

 to domestic animals, as wild animals feed undisturbed in parts in- 

 fested by the insect. Yet many of them, such as oxen and buffaloes, 

 horses and zebras, dogs and jackals, &c., possess somewhat of the 

 same nature.* Moreover it bites man and no danger follows. The 

 sensation experienced has not inaptly been likened to the sting of a 

 flea. When allowed to settle on the hand of man, all it is observed to 

 do is to insert its proboscis a little further than seems necessary to 

 draw blood. It then partially withdraws the dart, which assumes a 

 crimson hue. The mandibles now appear to be agitated ; the 

 shrunken body swells ; and, in a few seconds, the insect becomes 

 quite full, and quietly abandons its prey. The problem to be solved 

 is, what quality exists in domestication which renders domestic 

 animals obnoxious to this poison. Is man not as much a domestic 

 animal as a dog ? Is it the tzetze at all which kills the animal ? 



" Captain Vardon, of the Indian Army, one of the earlier pioneers 

 of the more interior parts of Southern Africa, was amongst the first to 

 decide the point ; for he rode his horse up a hill infested by tzetze, 

 and in twenty days his doubts were removed by the death of his 

 steed. 



''According to the statement of the celebrated explorers, Messrs. 

 Oswell and Livingstone, who were severe sufferers by the tzetze, the 

 following symptons are observed in the ox when bitten : — the eye runs, 

 the glands under the throat swell, the coat loses its gloss, there is a 

 peculiar flaccidity of the muscles generally, and emaciation com- 



* According to Dr. Livingstone, the tzetze " appears not to attack asses."—* Pro- 

 ceedings of the Entomological Society' for May 4th, 1857. 



