HISTOLOGY OF THE FERN 



113 



rhizome but are also continuous, through branches, in every 

 root and every leaf stem, the root hairs or rhizoids alone being 

 free from them. The canal system leading into the stems of 



FIG. 46. Epidermis from the under side of a leaf, showing the wavy outlines 

 of the epidermal cells, the veins () covered by thickened epidermal cells, and 

 guard cells (s /.) enclosing the stomata. (From Sedgwick and Wilson.) 



the fronds are the most important forming as they do the only 

 means of communication between the aerial frond and the 

 underground parts of the fern. 



