PTERIDOPHYTA. 



707 



Fig. 400.— Various Ferns. 



Xephrdlepis Diiffi.. 2 Trichomanes Lyallii. 3 Sorus of the same fern, with cup-shaped investment seen in longitudinal 

 section. * Rhipidopteris peltata. 6 Polypodium serpens. ^ Portion of frond of Gleichenia alpina. ? Schiztsa fistulosa. 

 ^ Botrychitim lanceolatujn . ^ Under side of a fragment of the frond of Gleichenia alpina; above the sporangia are 

 concealed by a tuft of scales, below they are exposed. 10 and 11 Fertile pinnule of Cyathea elegaiis. 12 Longitudinal 

 section of a snrus of Cyathea. is Sporangium of Cyathea. 1* Sporangium of Polypodium. is Sporangium of Schizcea, 

 " Under side of the prothallium of Aspienium. 1, 2, 4^ 6, e, 7, e natural size ; 3, s. 10, »i, 12, is, ", is^ " x 5-20. 



