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BIG GAME AND TSETSE FLIES 
Africa generally, down to Zululand. It is supposed that the 
word 4 tsetse ’ owes its origin to the characteristic buzzing sound 
made by the insect when flying or about to suck. Tsetse flies 
are brown or greyish-brown insects of about J inch to J inch 
in length. In all kinds there is a prominent sucking apparatus 
or proboscis projecting forwards horizontally from the head. 
The tsetse differ from ordinary blood-sucking flies in that 
during rest the wings lie closed flat over one another down 
the back. 
Some fifty years ago it was noticed that the bite of tsetse 
flies caused a fatal disease in domestic animals, and it was 
thought to be due to some peculiar poison injected by the 
insect while sucking blood. In 1895 Lieut.-Col. Bruce in Zulu- 
land showed that the disease called nagana in domestic animals 
was caused by the presence of vast numbers of a minute blood 
parasite ( Trypanosoma, brucei), which was carried to the 
domestic animals by the tsetse fly. This discovery has given 
to the study of the habits and distribution of the tsetse a great 
economic importance. It has, however, been discovered 
that the parasite causing the nagana disease can occur in blood- 
sucking flies other than in the tsetse. The late Capt. A. J. 
Haslam found the parasite Trypanosoma brucei in a certain 
blood-sucking fly (stomexys) which belongs to another genus. 
It was formerly believed that the tsetse laid eggs in the 
excreta of the buffalo, but Bruce showed that this is erroneous. 
The female tsetse does not lay eggs, but produces a fully 
grown yellow-coloured grub. This when born is active, and on 
finding a suitable hiding place, such as a small hole or crevice, 
changes in a few hours into a black quiescent pupa. The fly 
emerges from the pupa in about five or six weeks. The tsetse 
exhibits a great dislike to animal excreta, and natives have 
been known to plaster their domestic animals with such as a 
protection against the fly. It is obvious, therefore, that the 
idea of the fly breeding in dung arose simply in a wild guess. 
Tsetse flies of different species are widely distributed 
through many parts of Africa. They prefer low-lying bush 
country, and as a rule, although not invariably, near water. 
The fly is seldom found in open grass country. 
Tsetse is exceedingly local in occurrence, and in any district 
