CHAPTER XV 



PTERIDOPHYTES (FERNS, EQUISETA, AND CLUB MOSSES) 



The Pteridophyta are a very interesting and important division 

 of the plant kingdom, not only on account of their great beauty 

 and common occurrence but also because they are the undoubted 

 ancestors of the higher seed plants. These fernlike ancestors of 



FIG. 166. Maidenhair ferns (Adiantum) growing in a natural habitat 

 in the forest 



the pines and their allies, as well as of the flowering plants (like 

 the beans, mandrake, and clovers), date back to the coal period. 

 The special advances made by the Pteridophyta over the 

 plants below them relate to the much greater importance of 

 the sporophyte as compared with the gametophyte in the life 

 histories of all its members, and to the differentiation of the 



