276 ELEMENTARY STUDIES OF FERNS. 



A simple comparison might profitably be made between 

 the ferns and the mosses by showing how the leafy fern 

 which bears the spores corresponds, not to the leafy moss, 

 but to the stalk and capsule borne upon it, thus 



Leafy fern with spores =. stalk and capsule with spores, 

 arising on prothallus arising upon leafy moss by 



a sexual process. 

 Prothallus of fern = leafy moss. 



