BRYOPHYTJ^ 



107 



its oospores germinate there is formed a globular mass of 

 cells, every one of which is a spore mother cell (Fig. 90, C). 

 If an outer layer of mother cells should become sterile and 

 form a wall about the others, such a spore case as that of 



Fie. QO.-Coleochate. one of the green algae : A, a portion of the thallus, showing 

 oogonia with trichogynes (off), antheridia (an), and two enlarged biciliate sperms 

 (z); B, a fertilized oogonium containing oospore and invested by a tissue (r) 

 which has developed after fertilization ; C, an oospore which has germinated 

 and formed a mass of cells (probably a sporophyte), each one of which organizes 

 a biciliate zoospore (D).— After Prisgsheim. 



Riccia would be the result (Fig. 86, A). For such reasons 

 many believe that the Liverworts have been derived from 

 such forms as Cohocliate. 



67. The gametophyte. — Having considered the sporo- 

 phyte body as represented by the sporogonium, we must 

 consider the gametophyte body as represented by proto- 

 nema and leafy branch (gametophore). The gametophyte 

 results from the germination of an asexual spore, and in 

 the Mosses it is differentiated into protonema and leafy 

 gametophore (Figs. 81, 82, 102). Like the sporophyte, 



