ANIMAL-GALLS. 353 



of it in his Georgics,* of which the following is a transla- 

 tion, a little varied from Trapp : — 



Kound Mount Alburnus, green with shady oaks, 



And in the groves of Silariis, there flies 



An insect pest (named Oestrus by the Greeks, 



By us Asilns) : fierce with jarring hum 



It drives, pursuing, the aflrighted herd 



From glade to glade ; the air, the woods, the banks 



Of the dried river echo their loud bellowing. 



Had we not other instances to adduce, of similar terror 

 (Caused among sheep, deer, and horses, by insects of the 

 same genus, whi^h are ascertained not to peneti'ate the 

 skin, we should not have hesitated to conclude that A^al- 

 lisnieri and Eeaumur are right, and Mr. Bracey Clark 

 wrong. In the strictly similar instance of Eeindeer-fly 

 (^(Estrus tarandi, Linn.), we have the high authority of 

 Linngeus for the fact, that it lays its eggs upon the skin. 



" I remarked," he says, " with astonishment how greatly 

 the reindeer are incommoded in hot weather, insomuch 

 that they cannot stand still a minute, no not a moment, 

 without changing their posture, starting, puffing and blow- 

 ing continually, and all on account of a little fl}^ Even 

 though amongst a herd of perhaps five hundred reindeer, 

 there were not above ten of those flies, every one of the 

 herd trembled and kept pushing its neighbour about. The 

 fly, meanwhile, was trying every means to get at them ; 

 but it no sooner touched any part of their bodies, than they 

 made an immediate effort to shake it off. I caught one of 

 these insects as it was flying along with its tail protruded, 

 which had at its extremity a small linear oritice j)erfectly 

 white. The tail itself consisted of four or five tubular 

 joints, slipping into each other like a pocket spying-glass, 



* Est lucos Silari circa ilicibusque virentem 

 Plurimus Alburnum volitans, cui nomen asilo 

 Romanum est, CEstrum Graii vertere vocantes, 

 Asper, acerba sonans ; quo tota exterrita silvis 

 Diffugiunt armenta ; fm-it mugitibus sether 

 Concussus, sylveeque et sicci ripa Tanagri, 



Georg. lib. iii. 146. 

 9 * 



