III. ON THE INTKODUCED SPECIES. 



1. Definitions, Opinions, &c. 



Which of the species now seemingly wild in Britain 

 are aboriginal natives ? — Which among them ought to be 

 deemed introduced plants? — The answer to these two 

 queries is difficult ; and in regard to many of the plants 

 it can be given only with much uncertainty either way. 

 The synonymous terms native and indigenous are applied 

 to those species which are believed to exist in Britain 

 independently of human agency. And the non-synony- 

 mous terms introduced and naturalised are applicable to 

 species which were originally brought into Britain through 

 the instrumentality of mankind, whether intentionally or 

 accidentally. But recorders of localities, and other writers 

 on British plants, evince much ignorance and carelessness 

 in their use of these terms. 



To the category of Native Species we must unavoidably 

 assign all those in regard to which no grounds are now 

 seen for supposing that they were first brought into 

 Britain by human agency. The application of the term 

 is thus simply negative. It can rarely or never be 

 known, whether the species existed in Britain before the 

 advent of mankind, or have immigrated into this country 

 more recently ; and if the latter, whether their immigra- 

 tion has been effected by natural means of transport only, 



VOL. IV. K 



