12. YORKSHIRE. 129 



Ragwort I have known killed in the fame 

 manner. 



I likewife met with an inftance, here, of 

 a bed of decks being deflroyed by faine ; or 

 by mowing. The facl was, a large patch of 

 docks as thick as they could grow upon the 

 ground were liable to the bite of fwine (fome 

 fpccies of which will feed on them with avi- 

 dity) ; and what they left was repeatedly 

 mown off; perhaps twice or thrice in a fum- 

 mer, for a fuccefiion of years. At length 

 they vanilhed as by a charm ; and were fuc- 

 ceeded by a thick fward of the finer graffes. 



Perhaps neither the fwine nor the fithe 

 could be faid with flrictnefs to have killed 

 thefe docks , which, it appears to me, evi- 

 dently, died of age. No vegetable is everlaft- 

 ing. Some are annual, fome are biennial, 

 others perennial. But the age, or natural 

 life of perennial herbs has not perhaps been 

 attended to. We may however take it for 

 granted, without experience, that all plants 

 which propagate their fpecies by feed alone, 

 may be fubdued by perfevering to prevent 

 their feeding. All that we want to know 

 from experience is their feveral ages ; in <fr- 



VOL. II. K der 



