118 



POPULAR HISTORY OF LICHENS. 



of Tulasne, already cited, for almost all that we know of the 

 spermogories and pycnides, the sperm atia and stylospores, 

 of Lichens, and of certain minute parasitic species, whose 

 true nature and structure he has been the first to point out ; 

 and also for much valuable information regarding the mi- 

 nute anatomy of Lichens. Great assistance has also been 

 derived from the elaborate descriptions of Eries ( f Licheno- 

 graphia Europsea reformata/ 1831), as given by Tuckerman 

 in his ' Synopsis of the Lichenes of New England, the other 

 Northern States, and British America' (Cambridge, U.S. 

 1848). We have preserved, in the following descriptions, 

 the terminology of Schgerer and Leighton, both because it 

 economizes space, and serves to convey a much more accu- 

 rate idea of the organisms intended to be described, than 

 any popular or general language we could employ. The 

 student may overcome any etymological difficulties by having 

 recourse to a Latin or Greek dictionary. We avoid how- 

 ever, with a view to simplify the study of British Lichens 

 to the beginner, giving any synonyms or references except- 

 ing those which relate to the ' English Botany 9 of Sowerby 

 (1756) — for nearly a century a standard work on British 

 Botany, and which contains plates of all the British Lichens 

 then known. 



