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INTRODUCTION TO BOTANY 



and no such description is here attempted. In all leaves the 

 fibrovascular bundles extend throughout the leafstalk into 

 the leaves, where they are known as the veins of the leaf. 



FIG. 209. The rootstock of a fern 



The outer part of the stem is made up of hard tissue, and in the interior are also 



bundles of hard tissue (s) known as sclerenchyma ; numerous woody bundles (/.&) 



are. also surrounded by the large amount of pith 



FIG. 210. Diagram of cross section of a fern leaf 



On the underside of the leaf are the indusium (i) and the sporangia (s) ; within 

 the sporangia are the spores. After Engler and Prantl 



