200 VARIOUS SPECIES OF (ESTRUS. 



evinced by our cattle does not, in the opinion of 

 Mr. Bracey Clarke,* proceed from the infliction of a 

 painful wound, but solely from the alarm occasioned 

 by a peculiar sound emitted by the CEstri, while 

 hovering for the purpose of oviposition. This view 

 would corroborate the description given by Virgil, 

 both as regards the existence of such a sound, and 

 its apparent effect upon the herd. The remarkable 

 accuracy of the passage has induced Kirby and 

 Spencef to present it to their readers in the follow- 

 ing translation, which I transcribe, that you may have 

 the pleasure of comparing it with the original : — 



" Through waving groves, where Selo's ton-ent liows, 

 And where, Alborno, thy green Ilex grows. 

 Myriads of insects flutter in the gloom, 

 (ffistrus in Greece, Asilus named at Rome), 

 Fierce and of cruel hum. By the dire sound, 

 Driven from the woods and shady glens around. 

 The universal herds in terror fly ; 

 Their lowiugs shake the woods and shake the sky, 

 And Negros' arid shore." — Georgics, Book III. 



The whole history of the CEstri is singular ; and 

 the ox, the horse, and the sheep, in these countries, 

 are alike subject to their attack, but in different 

 ways. The species which attacks the ox {(E. bovis) 

 deposits its eggs on the back of the animal. These, 



* Linna^an Transactions, vol. xv. p. 407. 

 t Introduction, vol. i. p. 149. 



