156 



SCHIZAEACEAE 



[CH. 



there may be a special protective growth comparable as regards superficial 

 origin to the indusium of the Hymenophyllaceae, which completely covers 

 each sporangium, as in Lygodiwn. Prantl recognised each solitary sporangium 

 as constituting what he called a ''monangial sorus." It will be seen from the 



Fig. 440. Anemia Svv. A, A. Phyllitidis Sw., leaf-blade: B, A. aurita Sw., primary pinna of a 

 sterile leaf: C, A. citneata Kze., Habit. (After Diels, from Engler and Prantl.) 



development that in all the genera the origin of the sporangia is strictly 

 marginal, while the protective flaps are secondary developments formed 

 after the initiation of the sporangia, by outgrowths not truly marginal but 

 superficial. 



