T-7l. 



FiG. 83. Reproduction and Development of Ferns. 



A, Sporangium of Pteris> external view, showing stalk (s) and 

 annulus (an). 



B, the same, during dehiscence, the spores (sp) escaping. 



C, a germinating spore, showing the ruptured outer coat (.?/), and a 



