S2 THE TSETSE POISON. Chap. IV. 



terruptedly for months, and, do what we will, the poor animals 

 perish miserably. 



When opened, the cellular tissue on the surface of the body 

 beneath the skin is seen to be injected with ah*, as if a quantity 

 of soap-bubbles were scattered over it, or a dishonest awkward 

 butcher had been trying to make it look fat. The fat is of a 

 greenish-yellow colour and of an oily consistence. All the 

 muscles are flabby, and the heart often so soft that the fingers 

 may be made to meet through it. The lungs and liver partake 

 of the disease. The stomach and bowels are pale and empty, 

 and the gall-bladder is distended with bile. 



These symptoms seem to indicate what is probably the case, a 

 poison in the blood ; the germ of which enters when the proboscis 

 is inserted to draw blood. The poison-germ, contained in a bulb 

 at the root of the proboscis, seems capable, although very minute 

 in quantity, of reproducing itself, for the blood after death by 

 tsetse is very small in quantity, and scarcely stains the ha:i<!s in 

 dissection. I shall have by and by to mention another insect, 

 which by the same operation produces in the human subject both 

 vomiting and purging. 



The mule, ass, and goat enjoy the same immunity from the 

 tsetse as man and the game. Many large tribes on the Zambesi 

 can keep no domestic animals except the goat, in consequence 

 of the scourge existing in their country. Our children were 

 frequently bitten, yet suffered no harm ; and we saw around us 

 numbers of zebras, buffaloes, pigs, pallahs and other antelopes, 

 feeding quietly in the very habitat of the tsetse, yet as undis- 

 turbed by its bite as oxen are when they first receive the fatal 

 poison. There is not so much difference in the natures of the 

 horse and zebra, the buffalo and ox, the sheep and antelope, as to 

 afford any satisfactory explanation of the phenomenon. Is a man 

 not as much a domestic animal as a dog ? The curious feature 

 in the case, that dogs perish though fed on milk, whereas 

 the calves escape so long as they continue sucking, made us 

 imagine that the mischief might be produced by some plant in 

 the locality, and not by tsetse ; but Major Vardon, of the Madras 

 Army, settled that point by riding a horse up to a small hill 

 infested by the insect without allowing him time to graze, and, 

 though he only remained long enough to take a view of the 



