MetapJiyta Pteris. 1 1 5 



FIG. 44. Asplenium adiantum nigrwn. RHIZOME AND PINNAE. (Maout and 

 Decaisne.) 



\ 



examined it will be found that externally the rhizome is 

 covered by a single layer of tabular cells, the epidermis, 

 the cell-walls of which are very thick and of a deep brown 



