CHAPTER VII 
THE FERNS (PTERIDOPHYTA) 
THE Pteridophytes or Ferns, using the latter term in 
its widest sense, include those plants sometimes known 
as the Vascular Cryptogams, which while evidently re- 
lated to the mosses differ from them in the very much 
more highly developed sporophyte, which here becomes 
an independent plant. Indeed, it is the sporophyte or 
non-sexual generation of the ferns which is the plant 
as it is ordinarily understood, the gametophyte being 
usually small and inconspicuous and of short duration. 
It will be remembered that in considering the Bryo- 
phytes great differences were noted in the relative 
development of gametophyte and sporophyte; that 
while in Riccia, for example, the sporophyte is nothing 
more than a capsule filled with spores, in Anthoceros 
the spore-formation is subordinated to a considerable 
extent, and there is developed a well-marked assimila- 
tive issue, consisting of green cells with large intercellu- 
lar spaces, and stomata communicating with the outside 
as in the vascular plants. Moreover, this sporophyte is 
not limited in its growth, but continues to elongate as 
long as the gametophyte remains alive. Owing to the 
absence of a root, however, the sporophyte still remains 
‘dependent upon the gametophyte for water, and to 
some extent for food also; but the well-developed 
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