LICHENS. 



145 



None of the members of the various kinds of Mosses now described have any vascu- 



B 



Fig. 291. 



Fi-. 292. 



Fig. 291. a, Phytozoa, or male parts, in situ within the cells; b, the same, detached from the ce.l- 

 wall in the chara. 



Fig. 292. Marchantia Polymorpha, or Liverwort, with its broad frond, A, and organs of fructifica- 

 tion, B. 



lar tissue, but are wholly composed of cellular tissue of various forms. 



Lichens. This important class of plants are more particularly found in regions 

 so far north that more highly and more delicately formed plants cannot exist ; as in the 

 instance of the Iceland Moss (Cetraria Islandlcct), so useful to the reindeer in its native 

 regions, and employed as a medicinal agent in this country. It consists of a lobed leaf, 

 called Jrond, thallus, or blatemas, of various forms and degrees of consistence, and which 



Fig. 293. 



Fig. 294. 



Fig. 295. 



Fig. 296. 



Fig. 293. Lichen growing upon a piece of rotten wood. 



Fig. 294. The fructification of the Jungermannia. A, very young spor< 



calyptra ; B, the same, quite developed, with the hyulina rpe and bursting, and presenting 



view the inclosed spores. 



Fig. 295. Spiral fibres or elaters of the Jungermannia (Scale Moss.) f .. *v an A nf 



Fig- 296,-Acrostalagmus Cinnabarinus, very highly magnified, with the fructification at the end of 



the filaments. 



differs from the like organ in all higher members of the vegetable kingdom, in the 

 fact that not merelv a part but the whole of its intra-cuticular substance is devoted to 



VOL. II. 



