Page:Lake Ngami.djvu/479

Rh "From what I have seen of the tsetse," writes Mr. Oswell to me, "I believe that three or four flies are sufficient to kill a full-grown ox. We examined about twenty of ours that were bitten and died, and the appearances were similar in all. On raising the skin, we perceived a glairy appearance of the muscles and flesh, which were much wasted. The stomach and intestines were healthy; heart, lungs, and liver, sometimes all, but invariably one or the other, much diseased. The heart, in particular, attracted our attention. It was no longer a firm and muscular organ, but collapsed readily on compression, and had the appearance of flesh that had been steeped in water. The blood of the whole carcass was greatly diminished in quantity. Not more than twenty pints (a small pailful) were obtained from the largest ox, and this thick and albuminous; the hands, when plunged into it, came out free of stain. The poison would seem to grow in the blood, and, through the blood, affect the vital organs.

"A curious feature in the case is, that dogs, though reared on milk, die if bitten, while calves and other young sucking animals are safe as long as they suck. Man, and all the wild animals, escape with impunity. Can the poison be alkaline, and neutralized by the acid?"

we journeyed up the Teoge, we frequently observed crocodiles basking in the sun in the more secluded parts of the river. One day, while trying to trace a wounded