158 INDIRECT INJURIES CAUSED BY INSECTS. 



of a mercurial ointment used to destroy them. — In tro- 

 pical countries the sheep frequently suffer from the ants. 

 Bosnian relates that when in Guinea, if one of his was 

 attacked by them in the night, which often happened, it 

 was invariably destroyed, and was so expeditiously de- 

 voured that in the morning only the skeleton would be 

 left. 



Of our domestic animals the least infested by insects, 

 I mean as to the number of species that attack it, is the 

 sivine. With the exception of its louse, which seems to 

 annoy it principally by exciting a violent itching, it is 

 exposed to scarcely any other plague of this class, unless 

 we may suppose that it is the biting of flies, which in hot 

 weather drives it to " its wallowing in the mire." 



Under this head we may include the deer tribe, for, 

 though often wild, those kept in parks may strictly be 

 deemed domestic ; and the rein-deer is quite as much so 

 to the Laplander, as our oxen and kine are to us. We 

 learn from Reaumur that the fallow-deer is subject to the 

 attack of two species of gad-fly : one, which, like that of 

 the ox, deposits its eggs in an orifice it makes in the 

 skin of the animal, and so produces tumours ; and an- 

 other in imitation of that of the sheep, ovipositing in 

 such a manner that its larvae when hatched can make 

 their way into the head, where they take their station in 

 a cavity near the pharynx. He relates a curious notion 

 of the hunters with respect to these two species. Con- 

 ceiving them both to be the same, they imagine that 

 they mine for themselves a painful path under the skin 

 to the root of the horns ; which is their common rendez- 

 vous from all parts of the body; where, by uniting their 

 labours and gnawing indefatigably, they occasion the 



