118 INDIRECT INJURIES CAUSED BY INSECTS. 



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 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 bots (which is the vulgar name for the larvae and 

 pup^e 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 beneficial 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 

 sometimes of death. 



How troublesome and teasing is that cloud of flies (^An- 

 thorny ia meteorica) 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 Lap- 

 land, as we learn from Linne^, is the furious assault of the 

 minute horse-gnat {JJulex equinus L.), which infests these 

 beasts in infinite numbers, 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 . them in a 



1 De Geer, vi. '295. ^ Amcen. Acad. iii. 358. 



3 Linn. Flor, Lapp. 376. Lack. Lapp. i. 233, 234. This insect from Linne's 



description is probablv no Culex, but perhaps a SimuUum Latr. {Simulia 

 Meig. ) 



