jif) Mr. ClarkV Obfcrvations en the Genus Oefirm. 



General Qbfervatlom on the Oejiri. 



Havi>'g traced thefc animals feparately through their various 

 changes, it may not be improper to conclude the account by a ge- 

 neral review of their good or ill efTecls on the animals that arc 

 fubject to them. 



Though the attention of naturalifts is at prcfent chiefly occupied 

 with the formation of a nomenclature and defcriptions to every 

 object of the fcience; yet this, though difficult and highly import- 

 ant, is not fo much the ultimate aim of natural hiftory as a know- 

 ledge of their economy and properties ; as from thefe we are taught 

 the mofl: efFeclual means of avoiding the confequences of the inju- 

 rious, and of proteiSling fuch as can be ufefuUy applied to the pur- 

 pofes of mankind. 



If, after mature enquiry, the exiftence of the Oejrl fliould be 

 proved in a greater degree injurious than any fervice they can 

 afford, their numbers might be confiderably reduced, and a total 

 extirpation of fome of the fpecies would, I am difpofed to believe, 

 be not altogether impradlicable. 



The injury derived from their depredations is principally felt by 

 the tanners, whofe hides are often fo perforated by thefe animals 

 as to be confiderably damaged thereby ; and the lofs of a horfe or 

 .1 fhecp may fometimes perhaps be occafioned by the exiftence of 

 the other fpecies. 



If it were defirable to leflen their numbers, the following, I ap- 

 prehend, would be the mod fuccefsful means : 



The larva of the CE. Bovisy which breeds in the backs of the 

 horned cattle, is fo confpicuous that it is more eafily deftroyed than 

 the others: the injeftion of any corrofive liquor into the Jinus 



4 would 



