SPORES AND THALLIDIA. 



11 



Fig. 189.— Ferns. 



Nephi-oLcpm Uiqli. '^ Tnchomanes Lyelli. 3 Sorus of the same Fern with cup-sliaped iuvestiiieiit seen in longitudinal sectioB. 

 * Rhipidopteris peltata. ^ Polypodium serpens. ^ FinnA of Gleichenia alpina. t Schizceafistulosa. » Botrychium lancto- 

 latum. 9 Under side of a pinna of Gleichenia alpina ; in the two upper cavities the sporangia are covered by leaflets, in 

 tlie under ones they are exposed, lo, n Pinna of Cyathea elegans. 12 Longitudinal section through a Sorus and Cup of 

 Cyathea. is Sporangium of Cyathea. " Sporangium of Polypodium. is Sporangium of Schizcea. »« Under side of the 

 Prothallium of Spleenwort. », 2, 4, s, 6_ r^ 8 natural size ; », », 10, », 1-. ". ", ", '« niaguilled from 5 to 20 times. 



