136 Mr. Turner's Descriptions of Eight New British Lichens. 



intention here to enter into an enumeration of the various at- 

 tempts which had previously been made to subdivide the vast 

 tribe of Lichens, or even to offer any observations upon the 

 Acharian system, further than may be called forth by the parti- 

 cular individuals which I am about to describe. Such inquiries, 

 however interesting to myself, would lead me into a field far too 

 wide for my present object; and, as in describing the plants 

 themselves I shall have occasion to give the definitions of the 

 genera to which they belong, I will merely add, that I trust I 

 shall not be accused of presumption or of an idle itch for innova- 

 tion, in being the first who ventures to use in Britain a new ar- 

 rangement of these plants. No one is more deeply impressed 

 with a sense of the necessity of rigidly abstaining from all use- 

 less alteration of names, or multiplication of synonymy. Our 

 botanical nomenclature is already so extensive and intricate as 

 to be perplexing to all, even to those most conversant with the 

 subject, and to deter many from joining us in the prosecution of 

 the science ; yet considerations of this nature must not be allow- 

 ed to be carried too far. Every branch of human knowledge re- 

 quires in proportion to its development an extension of its tech- 

 nical terms, without which its progress would effectually be 

 checked. Had this been denied, the discoveries of Linnaeus or of 

 Hedwig themselves had been nipped in the bud ; and J must be 

 allowed to state it as my opinion, that many of the alterations 

 proposed by Dr. Acharius in the nomenclature of the Lichens, 

 however troublesome it may be to us at present to unlearn what 

 we have long since learned, will be found not less important in 

 extending the knowledge of these plants than his new system. 

 Upon the propriety, or rather the necessity, of subdividing the 

 numerous vegetables now arranged under the one vast genus, 

 Lichen, and I believe all botanists, who have bestowed upon 



the 



