LIFE HISTORY OF A FERN 
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coiled up from the tip. As the leaves grow they unroll, 
and in some ferns, at certain stages, they often closely re- 
semble the neck of a violin (Fig. in). The leaf -blade 
possesses veins of nbro-vascular bundles that pass down 
FIG. 112. Portions of the sporophylls of two ferns to show the sori. 
On the left Poly podium punctatum (L.)Sw.; on the right a variety of Pteris 
longifolia, with sporangia marginal on the pinnules. 
the leaf-stalk and through the stem to the roots. Because 
of the possession of these vascular bundles, ferns (and 
all other plants of which this is true) are called vas- 
cular plants. These leaves perform all the functions 
