PrEElDOPETTA. 



201 



422. The antherids and archegones resemtle those of the 

 Horsetails; however, in the highest order (Pepperworts) 

 the antherids become greatly reduced. 



423. The ferns are classified mainly upon the structure 



■Ss-:« ■:.-■/* 





Fio. 112.— A common Fern (Polypodium vulgare) showing the underground 

 root-hearing stem, and the leaves, one with round spore-dots on its lower sur- 

 face. Natural size. 



of their spore-bearing parts. Four orders may thus be 

 separated. 



424. The True Ferns {Order MKces) include very nearly 

 all the common fern-like plants of our woodlands and hill- 



