430 FERNS LESS, xxxi 



small that its very existence is unknown to a large propor- 

 tion of fern-collectors. 



It follows from what has just been said that the various 

 organs of a fern do not severally correspond with those of a 

 moss. The leaves of a moss are not homologous with those 

 of a fern, but are rather comparable to lobes of the pro- 

 thallus : in the same way the rhizoids of a moss correspond, 

 not with the complicated roots of the fern, but with the 

 rhizoids of the prothallus. 



