50 STRUCTURAL BOTANY 



cells is half-surrounded by a subsidiary cell, shaped like 

 a horseshoe. The subsidiary cell and guard-cells are 

 ultimately derived from a single mother-cell, which is 

 cut out from one of the epidermal cells by a curved 

 wall. 



The cells of the epidermis on both surfaces of the 

 leaf have undulating cell-walls fitting closely together. 



FIG. 24. Part of epidermis from the under-side of leaf of Male 

 Fern. Note the undulating cell-walls and numerous 

 chlorophyll - granules, n, nucleus of epidermal cell ; st, 

 storua. Magnified 105. (R. S.) 



The cells contain chlorophyll, as is generally the case 

 in the epidermis of Ferns, though less usual among 

 flowering plants. 



3. The Root 



The adventitious roots of the Male Fern arise, as we 

 have already seen, at the bases of the leaves, though 



