84 



VASCULAR CRYPTOGAMS 



there are" species with liarren and fertile leaves, differing from one 

 another in habit and in degree of segmentation ; in other heterophyllous 



Fig. 58.— Sori of Polypodiaceae (variously magnified), a, b, Adiantutjz ; c, Lindsaya ; d, e, Blechnuni ; 

 f,g, Cystopte7-is ; h. i, Davallia ; k, /, Cheilanthes ; w, n, Pteris ; 0, p, IVoodivardia ; g, Scolopen- 

 driuin; r,s, Asplenintn; t, Aspidhan ; n,v, IVoodsia ; w, Gymnogiamiite ; x, z, Polypoduan. 

 (After Luerssen.) 



ferns (species of Polypodium) both forms of leaf are fertile. A few of 

 the Polypodieas are arborescent '^Dicksonia L'Herit.). 



