PTERIDOPHYTA. 



707 



Fig. 400.— Various Ferns. 



1 Nepkrolepis Duffi,. 2 Trichomanes Lyallii. » Sorus of the same fern, with cap-shaped investment seen in longitudinal 

 section. * Bhipldopteris peltata. ^ Polypodium, serpens. ^ Portion of frond of Gleichenia alpina. ? Schizma fistulosa. 

 ^ Botrychium lanceolatum. « 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 elegans. 12 Longitudinal 

 section of a sorus of Cyathea. i3 Sporangium of Cyathea. 1* Sporangium of Polypodium. is Sporangium of Schizaea. 

 16 Under side of the prothallium of Asplenium. 1, 2^ 4^ 5, e^ 7, a natural size ; 3, 9. 10, 11, 12, 13^ 14^ 15^ le x 5 - 20. 



