346 



BOTANY OF THE LIVING PLANT 



the sporeling ; four form a hypobasal tier, which gives rise to the first 

 root and a suctorial organ called the foot. These parts are soon 

 distinguishable by their form and structure, and are seen in their 

 relative positions, but still enclosed in the enlarged venter of the 



archegonium, in Fig. 288. Soon the cotyledon and first root burst 

 their way out : the former expands as the first nutritive leaf, the latter 

 buries itself in the soil (Figs. 289, 290). At first the young Fern-Plant 

 is dependent upon the prothallus that encloses it, but by means of its 

 cotyledon and its root it soon becomes self-dependent, and the 



