152 HISTORY OF 



the season is favourable for them, they are seen 

 by myriads buzzing along, hitting against every 

 object that intercepts their flight. The mid-day 

 sun, however, seems too powerful for their con- 

 stitutions ; they then lurk under the leaves and 

 branches of some shady tree, but the willow seems 

 particularly their most favourite food ; there they 

 lurk in clusters, and seldom quit the tree till 

 they have devoured all its verdure. In those sea- 

 sons which are favourable to their propagation 

 they are seen in an evening as thick as flakes of 

 snow, and hitting against every object with a sort 

 of capricious blindness. Their duration, however, 

 is but short, as they never survive the season. 

 They begin to join shortly after they have been 

 let loose from their prison ; and when the female 

 is impregnated, she cautiously bores a hole in the 

 ground with an instrument fitted for that purpose 

 which she is furnished with at the tail, and there 

 deposits her eggs, generally to the number of 

 threescore. If the season and the soil be adapted 

 to their propagation, these soon multiply as alrea- 

 dy described, and go through the noxious stages 

 of their contemptible existence. This insect, 

 however, in its worm state, though prejudicial to 

 man, makes one of the chief repasts of the feather- 

 ed tribe, and is generally the first nourishment 

 with which they supply their young. Rooks and 

 hogs are particularly fond of these worms, and 

 devour them in great numbers. The inhabitants 

 of the county of Norfolk some time since went 

 into the practice of destroying their rookeries; but 

 in proportion as they destroyed one plague, they 



