82 APPENDIX. [sect. 



to us a novelty, and to Africa a scourge. This fly is so serious 

 a pest, that a waggon or a company of horsemen is liable to 

 be brought to a standstill by its ravages. It is not much 

 larger than the common house-fly, yet its bite is certain death 

 to the horse, ox, or dog. 



Our traveller lost forty- three oxen during one journey 

 from its ravages ; on another occasion, this little tyrant turned 

 him back ; and he was frequently obliged to travel by night in 

 order to escape its annoyance. The reason why he travelled 

 so far north from Linyanti before he turned to the west was as 

 much to avoid the tsetse as the slave-dealer's path. 



It does not hurt man, game of most kinds, sucking calves, 

 or the mule and ass. An animal wastes away after its bite, 

 and perishes from extreme exhaustion. Horses are especially 

 liable to injury. A person eating the flesh of cattle affected 

 by it, is subject to carbuncle ; even boiling does not destroy 

 the virus in the flesh. 



This insect-plague spreads over nearly seven degrees of 

 latitude. Linyanti and its neighbourhood are in the very cen- 

 tre of its habitat. Dr Livingstone concludes that large game, 

 especially elephants, take it into a district. The following facts 

 make him think so. It now exists on the Zambesi, in some 

 parts to such an extent, that the people can keep no domestic 

 animals except goats ; whereas the same districts teemed with 

 cattle in the palmy days of the Batoka tribes. Again, Londa 

 is free both from large game and tsetse ; yet the people have 

 no cattle. Hence he concludes that this insect migrates with 

 the larger game. 



Several other natural sciences are enriched by our traveller's 

 labours ; but in these, as in most others, he is as yet only the 

 acknowledged pioneer. 



He saw birds in immense numbers and varieties, finding 

 several new kinds on the Chobe and Leeambye. 



The quantities of fishes, reptiles, insects, &c. noticed, 

 and partially described, are bewildering. Yet all are made 



