THE TSETSE. 



435 



TSETSE. OlOiAna morsltans. a, Head, with parts of the mouth, b, Antenna, or feeler. (The objects are 

 diflerently magnified. The line underneath the figure of the Fly indicates the natural size of the Tsetse.) 



the purpose of repelling these blood-thirsty insects which selected me for their victim, leaving 

 my companions untouched. I have found the whole of the unprotected space round the neck 

 covered with their bites, and my ears thickly stained with blood from the effects of their 

 weapons. 



To this family belongs the terrible TSETSE, the curse of Southern Africa, which destroys 

 horses, dogs, and cows 

 by thousands, though it 

 causes no harm to man 

 or to any wild animal. 

 Fortunately, it is a very 

 local insect, its bound- 

 aries being as sharply 

 denned as if drawn on 

 a map, one sids of a 

 stream being infested 

 with this active insect, 

 while the other is per- 

 fectly free. The figure is 

 drawn most accurately. 



The following account of its habits and the effects of its bite are given by Dr. Living- 

 stone : "In the ox the bite produces no more immediate effects than in man. It does not 

 startle him as the gad-fly does ; but a few days afterwards the following symptoms supervene : 

 the eyes and the nose begin to run ; the coat stares as if the animal were cold ; a swelling 

 appears under the jaw, and sometimes at the navel ; and, though the animal continues to 

 graze, emaciation commences, accompanied with a peculiar flaccidity of the muscles ; and this 

 continues 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 con 

 dition often perish soon after the bite is inflicted, with staggering and blindness, as if the 

 brain were affected by it. Sudden changes of the temperature, produced by falls of rain, 

 seem to hasten the progress of the complaint ; but, in general, the emaciation goes on uninter- 

 ruptedly 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 air, 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 color, 

 and of an oily consistence. All the muscles are so flabby, and the heart often so soft, 

 that the fingers may be made to meet through it, and the lungs and liver partake of the 

 disease. The stomach and bowels are pale and empty, and the gall-bladder is distended 

 with bile." 



The insect which occasions these terrible results is hardly larger than a house-fly. It is 

 curious that, although horses perish under its bite, mules, asses, and goats escape injury, and 

 it seems that the bite of a single fly is sufficient to cause death. Another curious symptom is, 

 that the blood loses its redness, and hardly stains the hands of the person who dissects the 

 smitten animal. The source of all this mischief is to be found in a little poison-gland at 

 the base of the mouth, not larger than a mustard-seed, and yet infinitely more deadly than 

 the venom of the rattlesnake. The color of the Tsetse is brown, with a few yellow bars across 

 the abdomen. When it bites a man, the pain which it causes is very slight, and the worst 

 results are a trifling irritation not more severe than that caused by the bite of a gnat. 



A large insect is the BANDED HORNET-FLY. It is an example of the Asilidse, among which 

 are found the most gigantic specimens of the order. The body of these insects is long, and 

 clothed with stiff hairs. They are fierce and voracious, feeding mostly upon other insects 

 which they catch on the wing, and out of which they suck the vital fluids through their 

 powerful proboscis. One species of this family has been known to capture and carry off a 

 hive -bee, a remarkable instance of a stingless insect attacking and overcoming a creature so 

 formidably armed as the bee. Some of them are said to ,attack cattle after the manner of 



