zgG Mr. Clark'j Obfervatkns on the Genus Oejlrus. 



generally follow to the water, or difperfe to different parts of the 

 held. 



And fuch is the dread and apprehenfion in the cattle of this fly, 

 that I have feen one of them meet the herd when almoft driven 

 home, and turn them back, regardlefs of the (tones, flicks, and 

 noife of their drivers ; nor could they be flopped till they reached 

 their accuftomed retreat, in the water. 



When the oxen are yoked to the plough, the attack of this fly is 

 attended with real danger, as they become perfectly uncontroul- 

 able, and will often run with the plough directly forwards, through 

 the hedges, or whatever obftru&s their way. There is provided, 

 on this account, to many ploughs, a contrivance immediately to fet 

 them at liberty on fuch an occafion. 



The fingular fcene attending the attack of this fly on the herd, 

 has often been the fubject of poetical defcription ; but no one has 

 more naturally or elegantly delineated it than the bard of Mantua : 



Eft lucos Sllari circa, ilicibufque virentem 

 Plurimus Alburnum volitans, cui nomen Afilo 

 Romanum eft, Oeflron Graii vertere vocantes : 

 Afpcr, acerba fonans : quo tota cxterrita fylvis 

 Diffugiunt armenta ; furit mugitibus aether 

 Concuflus, fylvjeque et fieri ripa Tanagri. 



Georg. lib. iii. ver. 146 — 15 t. 



The heifers, fteers, and younger cattle, are the moll: frequently 

 attacked by this fly, and nave in general a greater number of botts 

 than others : — the ftrongeft and healthieft beads feem conftantly 

 to be preferred by it, and this is a criterion of goodnefs in much 

 efteem with the dealers in cattle*. 



* The choice of a found healthy fubjeft for the <!cpofition of the eggs, is probably 

 caufed by the folicitude of the parent for the fafetv of its offspring. 



And 



