INDIRECT INJURIES CAUSED BY INSECTS. 147 



was so exhausted by continual suction, that it fell, and 

 afterwards died in great agonies a . 



No quadruped is more infested by the gad-fly, some- 

 times also improperly called the breese b , than the horse. 

 In this country no fewer than three species attack it. 

 The most common sort, known by the name of the horse- 

 bee ( Gasterophilus Equi\ deposits its eggs (which being 

 covered with a slimy substance adhere to the hairs) on 

 such parts of the body as the animal can reach with its 

 tongue ; and thus, unconscious of what it is doing, it un- 

 warily introduces into its own citadel the troops of its 

 enemy. Another species (G. hcemorrlioidalis) is still 

 more troublesome to it, ovipositing upon the lips ; and 

 in its endeavours to effect this, from the excessive titilla- 

 tion it occasions, giving the poor beast the most distress- 

 ing uneasiness. At the sight of this fly horses are always 

 much agitated, tossing their heads about in the air to 

 drive it away ; and, if this does not answer, galloping off 

 to a distant part of their pasture, and, as their last re- 

 source, taking refuge in the water, where the gad-flies 

 never follow them. We learn from Reaumur, that in 

 France the grooms, when they observe any bots (which 

 is the vulgar name for the larvae and pupae of these flies) 

 about the anus of a horse or in its dung, thrust their 

 hand into the passage to search for more ; but this seems 

 a useless precaution, which must occasion the animal 

 great pain to answer no good end : for when the bots 

 are passing through the body, having ceased feeding, 

 they can do no further injury. In Sweden, as De Geer 

 informs us, they act much more sensibly : those that 



a De Geer, vii. 158. 



b See Mr. W. S. MacLeay in Linn. Trans, xiv. 355. 

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