PTEKIDOPHYTA. 



707 



Fig. 400.— Various KeriiB. 



I NephrolepU Duß. 3 Trichomaiies Lyallii. * Sorus of the same fern, with cup-shaped investment seen in longitudinal 

 section. * Jthipidopteris peltata. * Polypodium serpens. « Portion of frond of Gleichenia alpina. T Schizcea fistulo&a. 

 * Botrychium lanceolatmn. • Under side of a fragment of the frond of Gleichenia alpina; above the sporangia are 

 concealed hy a tuft of scales, below they are exposed, lo and n Fertile pinnulu of Cyatkea eleyans. 12 Longitudinal 

 section of a sorus of Cyathea. 1» Sporangium of Cyathea. " Sporangium of Polypodium. 's Sporangium of Schizcea. 

 >• Underside of the pruthallium of Aspleniunu 1, 2, \ «, e^ t, b natural size; «. ». w, ", ", I3, H. i^, " x 5-20. 



