PTERIDOPHYTA. 



707 



Fig. 400.— Various Ferns. 



1 Nephrolepis Duffl. 2 Tnehomanes LyallU. * Sorus of the same fern, with cup-ahaped investment seen in longitudinal 

 section. * Shipidopteris peltata. ^ Polypodiwm serpens. ' VoTtlou ot ironi ot Oleichenia alpina. i Schizosajlstnlosa. 

 8 BotryahiUTn lanceolatwm. 9 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, i" and " Fertile pinnule of Cyathea elegam. 12 Longitudinal 

 section of a sorus of Cyathea. is Sporangium of Cyathea. " Sporangium of Polypodium. 16 Sporangium of Schizcea. 

 16 Under side of the prothallium of Asplenium. 1, 2, 4^ 6, 6_ 7, 8 natural size ; s, s. 10, n, 12, is, w, is, is x 6-20. 



