24 



POPULAR HISTORY OF LICHENS. 



stitutiones Rei Herbarise/ they werefor the first time collected 

 into a separate group, to which he gave the term Lichen. 

 This term, though its derivation has been given variously by 

 different authors, is probably derived from the Greek word 

 Xeifflv, leiclien or lichen, a wart, which the fructification of 

 this group of plants frequently resembles. This group, or 

 family, Lichen, did not however include all the genera or 

 species of the family as now known • certain of them, having 

 a rigid or somewhat coral-like consistence or appearance, he 

 dissociated under the name Coralloides, a group in which he 

 included also some sections of the fungus or Mushroom 

 family. About forty years subsequently Dillenius, in his 

 classic ' Historia Muscorum/ further subdivided the family 

 by constituting his sections TJsnea, Coralloides, and Liche- 

 noides ; with^ these however were associated certain sections 

 of cognate cryptogamic families, in this case the Hepatica 

 and Conferva. The illustrious Linnseus preferred embracing 

 all the Lichens under a single genus, fjichen, w 7 hich he how- 

 ever subdivided into eight sections, according to the cha- 

 racters of the vegetative system, or thallus. Upon the 

 latter, up to this period, Lichenologists had based their 

 classification and nomenclature;" but HeaSvig and Gsertner, 

 whose w r orks are next in order of date, carefully examined 



