352 INSECT ARCHITECTURE. 



tlie deposition of the egg is not attended by much pain, 

 unless, as he adds, some very sensible nervous fibres have 

 been wounded. According to this view, we must not esti- 

 mate the pain produced by the thickness of the instrument ; 

 for the sting of a wasp, or a bee, although very consider- 

 ably smaller than the ovipositor of the ox-fly, causes a very 

 pungent pain. It is, in the latter case, the poison infused 

 by the sting, rather than the wound, which occasions the 

 pain ; and Vallisnieri is of opinion that the ox-fly emits 

 some acrid matter along with her eggs, but there is no 

 proof of this beyond conjecture. 



It ought to be remarked, however, that cattle have very 

 thick hides, which are so far from being acutely sensitive 

 of pain, that in countries where they are put to draw 

 ploughs and waggons, they find a whip inefi'ectual to drive 

 them, and have to use a goad, in form of an iron needle, at 

 the end of a stick. Were the pain inflicted by the fly very 

 acute, it would find it next to impossible to lay thirty or 

 forty eggs without being killed by the strokes of the ox's 

 tail ; for though Vallisnieri supposes that the fly is shrewd 

 enough to choose such places as the tail cannot reach, 

 Eeaumur saw a cow repeatedly flap its tail upon a part full 

 of the gall-bumps ; and in another instance he saw a heifer 

 beat away a party of common flies from a part where there 

 were seven or eight gall-bumps. He concludes, therefore, 

 with much plausibility, that these two beasts would have 

 treated the ox-flies in the same way, if they had given them 

 pain when depositing their eggs. 



The extraordinary effects produced upon cattle, on the 

 appearance of one of these flies, would certainly lead us to 

 conclude that the pain inflicted is excruciating. Most of 

 our readers may recollect to have seen, in the summer 

 months, a whole herd of cattle start off across a field in full 

 gallop, as if they were racing, — their movements indescri- 

 bably awkward — their tails being poked out behind them 

 as straight and stiff as a post, and their necks stretched to 

 their utmost length. All this consternation has been 

 known, from the earliest times, to be produced by the fly 

 we are describing. Yirgil gives a correct and lively picture 



