XLI] 



DRYOPTERIS 



125 



has more numerous narrower cells, and lies to the right. A comparison of Fig. 563 of 

 sporangia of the Cyatheaceae, or of Fig. 576, of sporangia of Dipteris, with the drawings 

 of Dryopteris (Fig. 657), in regard to the points mentioned, will show that Dryopteris ^till 

 retains traces of the oblique annulus, though in the adult sporangium the ring is interrupted, 

 and the sporangium has apparently, though not exactly, symmetrical sides. 



Fig. 657. Later stages in the development of the sporangium of 

 Dryopteris filix-vias (after Kny). i=the primary segmentation 

 completed. -2 = the spore-mother cells rounded off. 3, 4 = sporan- 

 gia of about the same age as 2, seen from without. 3 = apical view. 

 4 (z = presenting the distal or peripheral face. 4 /; = presenting the 

 proximal or central face. 5, 6, 7 = the sporogenous group. 



On the spore-output, which is normal for the Male Shield Fern, there is 

 nothing to remark. But the presence of a perispore is important (Fig. 658). 

 This deposit on the spore-wall is seen in the Male Shield Fern, and it 

 is present also in the Woodsieae, though it is absent in the Cyatheaceae. 

 Hannig {I.e. p. 340), in summing up the results of his observations on the 

 perispore, shows that it is characteristic of certain relatively advanced groups 

 of Ferns, and in particular of the Asplenieae and Aspidieae. It is, however, 

 absent in the great majority of Ferns, particularly in all those that are held 

 as primitive. It is also wanting in those Ferns which I have designated the 

 Marginales. It seems to be the fact that it came into existence in that very 



