BRYOPHYTES 



79 



different kind of body, but 

 resembles a liverwort body 

 that has not fully devel- 

 oped. This failure of most 

 Mosses to develop bodies 

 to the mature liverwort 

 stage is probably associ- 

 ated with the fact that 

 the gametophore bears 

 leaves and the chief work 

 of food manufacture is 

 done no longer by the pros- 

 trate body. 



The picture of a moss, 

 therefore, is a delicate, 

 prostrate, branching, green 

 filament (which most peo- 

 ple do not see), from which 

 arise numerous vertical 

 leafy branches (which most 

 people regard as the whole 

 plant), and since these 



leafy branches are gametophores, they bear the sex-organs. 

 There is some excuse for regarding the branching gameto- 

 phore as the whole plant, for 

 it sends out its own rhizoids 

 into the substratum, the 

 delicate green filament from 

 which it arose dies, and the 

 gametophore becomes com- 

 pletely independent (Fig. 

 61). In addition to this, 

 the gametophore can repro- 

 duce extensively by vegetative multiplication, so that 

 masses and " beds " of moss are formed. In fact, most 



FIG. 61. A, a leafy branch (gametophore) 

 that has become independent by putting 

 out its own rhizoids ; B, a rosette of 

 leaves surrounding a group of sex-organs 

 (forming the so-called "moss flower"). 



FIG. 62. Tips of leafy branches of a 

 moss, one of them bearing a group of 

 sex-organs surrounded by a rosette of 

 modified 'leaves. 



