CRYPTOGAMS 



423 



plant at once commences, but in most of the Musci a branched, 

 filamentous PROTONEMA is first produced, composed of cells containing 



an P 



Jl 



FIG. 377. Funarin liyyromctrim. A, Germinating spore ; ex, exine ; /}, protonema ; kn, buds ; 

 r, rhizoids ; s, spore. (After MULLER-THURGAU ; magnified.) 



chlorophyll (Fig. 377 r). The green, filamentous protonema gives 

 rise to branched, colourless rhizoids (r), which penetrate the sub- 

 stratum. The MOSS-PLANTS arise from buds developed on the 

 protonema at the base of the branches. 

 Protonema and Moss-plant, in spite of 

 the difference in appearance between 

 them, together represent the sexual 

 generation. Many Liverworts possess 

 a thallus consisting of dichotomously 

 branching lobes, which is attached to 

 the substratum at its base or on the 

 under side by means of rhizoids, thus 

 repeating the vegetative structure of 

 many Algae (Fig. 379). In other 

 Hepaticae, on the other hand, and in all 

 the Musci, there exists a distinct differ- 

 entiation into Stem and leaves (FigS. pio. 378. Phaseumcuspulntum.ini, Anther. 

 385, 392). In no instance, however, idia ; or, archegonia at the apex of the 

 r j ,. r bifurcated moss stem ; '/, leaves ;p, para- 



are true roots formed consisting of physes (Aft ,, H( , KV1 , ISTER , x 45 .) 

 a tissue of cells, but in their stead 



rhizoids, consisting of colourless branching filaments, the main function 

 of which is to attach the plant to the substratum. The Bryophytes, 

 in this respect, differ essentially from the Pteridophytes, which are 

 provided with true roots. The stems and leaves of Mosses are also 



