EXPLANATION OF THE PLATES. 

 Plates V-VII. — Polypody. Polypodium vulgare. Plate V. — 1-6. Young 

 leaves and plants in early stages of development. Plate VI. — i, 2. Young 

 leaves in later stages of development, i. Leaf with epidermis removed, 

 showing venation. Plate VII. — i. Mature fertile leaf. 2. Fertile pinna, 

 X 2i. 



