270 



MORPHOLOGY. 



the sexual phase of the pbirit (gametophyte) was the prominent one, 

 ami consiskM.l of either a thallus or a leafy axis, hiit in either case it bore the 

 sexual organs and led an independent existence; that is it was capable of ob- 

 taining its nourishment from the soil or water by means of organs of absorp- 

 tion belonging to itself, and it also performed the office of photosynthesis. 



560. The spore-bearing phase (sporophyte) of the liverworts and mosses, 

 on the other hand, is quite small as compared with the sexual stage, and it is 



s. 



s. 



>y4 



:& 



Fig. 312. 



Young embryo of fern (Adiantnm cnncinnuin) in enlarged venter of the archegonlum. S, 

 stem ; 7., first leaf or cotyledon ; /i', root ; -/■', tuut. 



completely <lcpeii<k-iit on the srxual sta^e for its nourishment, remaining at- 

 tached permanently tlirougliout all its ilevelopment, by means of the organ 

 called a foot, and it ilies after the sporrs arr mature. 



561. Now in the ferns we see several strikinj^ differences. In the first 

 place, as we have already observed, the spore-bearing phase (sporophyte) of 



