THE HOMOSPOROUS LEPTOSPORANGIATM 



38s 



ination is like that of the Polypodiacese, and a filament is first 

 formed, after which the flat prothallium grows for a time by 

 a single apical cell, which is finally replaced by a group of mar- 

 ginal cells. In A}ieimia and Mohria the growing point lies on 

 one side, so that the prothallium is not heart-shaped. In Ly- 

 godiiim, however, the prothallium has the ordinary form. 



The development of the antheridia has been studied by Kny 

 (4) in Anemiia hirta. The only difference between this and 



Fig. 223. — Aneimia hirsuta. A, Section of the rhizome, X30; B, part of the central 



region, X300. 



the normal antheridium of the Polypodiaceae is that in Aueiuiia 

 the first wall is always flat instead of funnel-shaped, and the 

 basal cell of the antheridium is therefore disc-shaped. The 

 archegonia appear to correspond exactly with those of the Poly- 

 podiaceae. 



The genus Schiccra, to judge from 5^. pusilla (Britton and 

 Taylor (i)), and S. dichotoma (Thomas (i)), differs mark- 



