PTERIDOPHYTA 



247 



membrane (Intine), the cuticularized exine or " Exospore," and the 

 outermost sculptured coat or perinium ("Epispore") which some- 



sp 



FIG. 212. Struthiopteris Germanica. A, B, germinating spores, with perinium 

 removed ( x 300) . C, young gametophyte ( X 100) . D, E, older stages with apical 

 cell, a; (X 300). F, small female gametophyte, seen from below; r, rhizoids; ar, 

 archegonia. 



times becomes detached from the exospore. In case the spore con- 

 tains chlorophyll at maturity the germination is usually rapid ; in 



