INDIRECT INJURIES CAUSED BY INSECTS. 117 



merable wounds made by the knives and lancets of various 

 horse-flies {Tabanus L.), which assail him as he goes, and 

 allow him no respite^; and consider that even this is nothing 

 to what he suffers in other climates from the same pest. In 

 North America, vast clouds of different species — so abundant 

 as to obscure every distant object, and so severe in their bite 

 as to merit the appellation of burning flies — cover and tor- 

 ment the horses to such a degree as to excite compassion even 

 in the hearts of the pack-horsemen. Some of them are 

 nearly as big as humble-bees ; and, when they pierce the 

 skin and veins of the unhappy beast, make so large an orifice 

 that, besides what they suck, the blood flows down its neck, 

 sides, and shoulders in large drops like tears, till, to use 

 Bartram's expression, " they are all in a gore of blood." 

 Both the dog-tick and the American tick before mentioned, 

 especially the latter, 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, some- 

 times 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 {CEstrus 

 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. iKEmor- 

 rhoidalis) is still more troublesome to it, ovipositing upon the 

 lips ; and in its endeavours to effect this, from the excessive 

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

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



1 Once travelling tlirovigh Cambridgeshire with a brother entomologist in a 

 gig, our horse was in the condition here described, from the attack of Tabanus 

 rusticus. 



2 De Geer, vii. 158. 



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



I 3 



