MOSSES, LIVERWORTS, AND FERNS 263 



Its cells contain chloroplasts and can manufacture their own 

 food. Since this filament precedes the leafy moss plant, it is 

 called the protonema, which means "first thread" (fig. 203, J). 



FIG. 203. The life cycle of a moss plant 



A, branching protonema, magnified 50 diameters. B and b, protonema producing 

 buds (1, 2, and 3) , rhizoids (rh) , and underground branches (u) ; ^magnified 40 diame- 

 ters. (7, adult leafy plants (Lp), upon which are the sporophytes (s) with their cap- 

 sules (caps), in which spores are borne, the capsule tip being covered by the hood, 

 or calyptra (cat) ; natural size. D and E, enlarged capsules with the mouth, or 

 peristome (p), from which the teeth (t) extend ; magnified 25 diameters. All are 

 the moss Atrichum undulatum except D, which is Fissidens adiantoides. A and 

 B from Bonnier and Sablon ; G, D, and E from Braithwaite 



