114 INDIRECT INJURIES CAUSED BY INSECTS. 



also infest the horse. Kalm affirms, that he has seen the under parts of 

 the belly, and other places of the body, so covered by them, that he 

 could not introduce the point of a knife between them. They were 

 deeply buried in the flesh ; and in one instance that he witnessed, the 

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

 afterwards died in great agonies.^ 



No quadruped is more infested by the gad- or bot-fly, sometimes also 

 improperly called the breese-, 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 (^(Estrus 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 unwarily introduces into its own citadel the troops of its enemy. 

 Another species ((E. hamorrhoidalis) is still more troublesome to it, ovi- 

 positing upon the lips; and in its endeavors to effect this, from the 

 excessive titillation it occasions, giving the poor beast the most distressing 

 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, gallopping off to a distant part of their pasture, and, as their last 

 resource, 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 hots (which is the vulgar name for the larva? and pupaj 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 have the care of horses are accustomed to clean their 

 mouths and throats with a particular kind of brush, by which method they 

 free them from these disagreeable inmates before they have got into the 

 stomach, or can be at all prejudicial to them.^ 



Providence has doubtless created these animals to answer some benefi- 

 cial purpose ; and Mr. Clark's judicious conjectures are an index which 

 points to the very kind of good our cattle may derive from them, as acting 

 the part of perpetual stimuli or blisters : yet when they exceed certain 

 limits, as is often the case with similar animals employed for purposes 

 equally beneficial, they become certainly the causes of disease, and some- 

 times of death. 



How troublesome and teasing is that cloud of flies (Antho?nyid meteor- 

 ica) which you must often have noticed in your summer rides hovering 

 round the head and neck of your horse, accompanying him as he goes, 

 and causing a perpetual tossing of the former !"* — And still more annoying 

 in Lapland, as we learn from Linne^, is the furious assault of the minute 

 horse-gnat (^Culer cquinus L.), which infests these beasts in infinite num- 

 bers, running under the mane and amongst the hair, and piercing the skin 

 to suck their blood. — An insect of the same genus is related to attack 



> De Geer, vii. 1.5R. » See Mr. \V. S. MacLeay in Linn. Trans. liv. 355, 



3 De Geer, vi. 295. * Ammn. Acad. iii. 358. 



* Linn. Flor. Lapp. 376. Lack. Lapp. i. 233, 234. This insect from Linn6's descrip- 

 lion is probably no Cu/«i, but perhaps a SimuHum Latr. {Simulia Meig.) 



