SPORES AND THALLIDIA. 



11 



ij'ig. ia9. — i'erns. 



Nephroiepis Duji. '^ Trickomanes Lyelli. 8 Sorus of the same Fern with cup-shaped investment seen in longitudinal section. 

 * Rhipidopteris peltata. ^ Polypodium serpens. * Pinna of Gleichenia alpina. ' Schizcea Jistulosa. s Botrychium lanceo- 

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

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

 CyatJiea. w Sporangium of Cyathea. 1* Sporaugium of Polypodium. is Sporangium of Schizcea. lo Under side of the 

 Prothallium of Spleenwort. 1, ^, *, 6, 6, y, a natural size ; s, 9, 10, 11^ la, is, 14^ is, u magnified from 6 to 20 times. 



