CHAPTER I 
FERNS 
The plants included in this work form, together, a group 
known to botanists as Vascular Cryptogams, and have certain 
characters in common by which they are distinguished from 
other groups of plants, but among themselves they present 
a considerable range of variation in structure, and no one 
who knows anything of botanical classification would think 
of associating with ferns such plants as Marsilia, Isoetes , or 
Psilotum. The connection will be explained further on ; but 
restricting ourselves meantime to the ferns, though most 
readers are familiar with them as a group, there are many 
who, while they recognise a plant as a fern, can give no 
definite character which identifies it as such, or which dis- 
tinguishes it from other plants resembling ferns. This is not 
because they possess no such character, but rather because 
their reproductive parts are so small as to be difficult to 
understand aright. Anyone who examines a fertile frond of 
the common Bracken will find that the margin all along is 
closely folded back upon the underside of the frond, and that 
under this reflexed edge there are numerous small bodies 
which, when examined under a magnifying glass, are found 
to be cases containing abundant dust-like particles, differing 
in structure from true seeds, but generally supposed to act as 
such. If the common scented fern be examined, it will be 
found to have these sporangia , or capsules , as they are called, 
under the reflexed edge all along the upper part of the frond 
only, while in the larger tree ferns, and in many other ferns, 
they are arranged in round dots which have certain fixed 
positions on the under surface of the frond. 
e 
s. F. S. A. 
