CRYPTOGAMS 



203 



have water only when dew or rain falls. Other kiniLs live 

 111 the crevices of bark on tree trunks ; others on soil. The 

 Sphagnum Mosses live in bogs, of which tliey sometimes 

 form the chief vegetation. Peat from 

 these bogs (used for fuel in some coun- 

 tries) is to a considerable extent made 

 up of the dead stems and leaves of these 

 Mosses. 



474. Reproduction is essentially the same 

 ill Mot.ses as in Liverworts. On the end 



of the stem, usually, 

 at the proper sea- 

 son archeyonia (Fig. 

 341) are found. An- 

 theridia (Fig. 342) 

 arise in a similar 

 position ; but in 

 most species the 



342. (iroupof aiitheiiilia : ((/) , i ■ i j? 



and sterile filaments ^WO kmds of Or- 



(/) on the end of a gans OCCUr OU dif- 



Moss stem. „ j , , mi 



fereut shoots, ihe 

 antherozoid is motile by means of two cilia, and reaches 

 the archegonium and finally the egg cell when the plants 

 are wet. Fertilization 

 results, as iu Liverworts, 

 in the production of a 

 (usually long - stalked) 

 sporogonium (Fig. 340). 

 The ujjper part of tlie old 

 archegonium may be car- 

 ried up on the growing 

 sporogonium as a cap 

 (calyptra, c). The spore 

 capsule opens for libera- 

 tion of the spores by the 

 displacement of a lid (^operculum, o) in most Mosses. 



475. When the sj^ore germinates it gives rise, not to the 

 Moss shoot directly, but to a mauy-branched filamentous 



341. Archegonkini 

 of a Moss: 

 e, egg cell ; 

 n, neck ; ?, 

 lid (opening 

 before fertil- 

 ization). 

 — Sachs. 



:343. 



Protonenia of Moss: ft, bud of Moss 

 shoot. — Fkank. 



