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, A). 



FIG. 203. The life cycle of a moss plant 



.1 . branching protonema, magnified 50 diameters. /' and b, protonema producing 

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

 ters. C, adult leafy plants (/./>), npon which are the sporophytes (*) with their eap- 

 Hules (cupif), in which spores are borne, the capsule tip being covered by the hood, 

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

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

 the moss Atrichum unditlutitm except />, which is Fixxiilen* adiantoides. A and 

 B from Bonnier and Sablon ; C', D, and E from Braithwaite 



