THE HOMOSPOROUS LEPTOSPORANGIAT1E 



385 



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 Aneimia and Mohria the growing point lies on 

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

 godium, however, the prothallium has the ordinary form. 



The development of the antheridia has been studied by Kny 

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



en p n 



FIG. 223. Aneimia hirsuta. A, Section of the rhizome, X3o; B, part of the central 



region, 



the normal antheridium of the Polypodiacese is that in Aneimia 

 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- 

 podiacese. 



The genus Schizcea, to judge from S. pusilla (Britton and 

 Taylor (i)), and $, dichotoma (Thomas (i)), differs mark- 



