516 



BOTANY OF THE LIVING PLANT 



Fig. 407. 



Microsporangium of Selaginella apus, in 

 median vertical section, containing numerous 

 microspores. The ligule is seen in Figs. 407, 

 408, as a small tongue-like bodv, rising from 

 the base of the leaf . (X55.) (After Miss Lyon.) 



Fig. 408. 



Megasporangium of Selaginella apus, in median 

 vertical section, showing three of the four mega- 

 spores. (x2i.) (After Miss Lyon.) 



Fig. 409. 



A, B = radial sections through young sporangia. C = transverse section of one 

 more advanced. D — tangential section. E =radial section of an older sporangium, 

 with ligule : the tapetum is shaded, and the sporogenotrs cells lie within. (A , B, C, 

 D = 35o; £ = 200.) F. O. B. 



