THE TSETSfi-FLY 253 



(lays' journey to the north of the Ngami, when both horses and 

 cattle were bitten by the fly, and the party were in consequence 

 compelled to make a hasty retreat. One of the number was 

 thus deprived of as many as thirty-six horses, excellent hunters, 

 and all sustained heavy losses in cattle. 



A most remarkable featm-e in the bite of the tsetse is its 

 perfect harmlessness in man and wild animals, and even calves, 

 so long as they continue to suck the cow. The mule, ass, and 

 goat enjoy likewise the same immunity, and many large tribes 

 on the Zambesi can keep no domestic animals except the latter, 

 in consequence of the scourge existing in their country. Dr. 

 Livingstone's children were frequently bitten, yet suffered no 

 liarm, and he saw around him numbers of zebras, buffaloes, 

 ])igs, pallahs and other antelopes, feeding quietly in the very 

 liabitat of the tsetse, yet as undisturbed by its bite as oxen are 

 when they first receive the fatal poison, which acts in the fol- 

 lowing manner. After a few days the eyes and nose begin to 

 rim, the coat stares as if the animal were cold, a swelling appears 

 under the jaw, and, though the animal continues to graze, emaci- 

 ation commences, accompanied with a peculiar flaccidity of the 

 muscles; and this proceeds unchecked until, perhaps months 

 afterwards, purging comes on, and the animal, no longer able to 

 graze, perishes in a state of extreme exhaustion. Those which 

 are in good condition often perish, soon after the wound is 

 inflicted, with staggering and blindness, as if the brain were 

 affected by it. Sudden changes of temperature, produced by 

 falls of rain, seem to hasten the progress of the complaint, but in 

 general the emaciation goes on uninterruptedly for months; and 

 do what one may, the poor animals perish miserably, as there is 

 no cure yet known for the disease. 



Had any one of our indigenous flies similar poisonous qualities 

 we should never have been able to escape from barbarism ; if, by 

 any fatal chance, the tsetse were to settle among us, our prosperity 

 would soon be at an end, and our civilisation imperilled ! Re- 

 flections such as these are well calculated to humble our pride 

 and check our presumption ! 



The Abyssinian Tsalt-salya or Zimb, described by Bruce, 

 seems identical with the tsetse, or produces at least similar 

 symptoms. At the season when this plague makes its appear- 

 ance, all the inhabitants along the sea-coast, from Melinde to 



