INTRODUCTION. 
IMHE Ferns form a gi'cnp of plants which arc considered as the most highly developed of that 
^ large class which produce no visible flowers, and of which other familiar and recognizable 
groups are the Mosses, the Lichens, the Sea-weeds, and the Funguses. These, as a whole, were 
weU named Cryptogamous plants by Linnaeus, inasmuch as the process by which their seeds, or 
the equivalent of seeds, are produced, are hidden and mysterious, compared with what we are 
enabled to observe in those orders of vegetation, — higher orders as -they are termed, — which 
produce perfect flowers as the medium by whose agency their seeds are organised. 
Among the groups into which Cryptogamous plants are se]Darated for the convenience of 
classification, the Ferns are known by possessing a certain degree of vascularity in their 
structure, and by producing spores — that is minute reproductive atoms — of only one kind, 
within little one-ceUed cases or receptacles that are collected into groups occupying a portion, 
rarely the whole, of either the hack or the margin of their leaves. The true Ferns have their 
young leaves rolled up spirally, and in gradually imfolding present the form of a crozier ; hut 
a small group, dift'ering chiefly in having their young parts folded and not rolled up, and which 
may he considered as spurious Ferns, are conveniently associated with them. 
In briefly describing what is the structiu’e of Ferns, and the terms applied to the modifications 
of their respective parts, with sufiicient distinctness to render the descriptions of the species 
which occupy another part of these pages the more inteUigihle, it will he convenient to con- 
sider them as consisting of four series of organs — the roots, the stems, the fronds, and the 
fructification. 
The roots of Ferns are fibrous, and we believe, in all the true Ferns, are covered with a 
pile of soft close hairs or down, not unfrequently of a ferruginous or rust-colour, and they 
generally grow more or less matted or entangled, especially if they are in contact with any hard 
surface, such as the rocks or tree-trunks on which many of them grow naturally ; and the same 
is observed when they are placed under the circumstances which attend their artificial culti- 
vation. The true roots must not be confounded with the stems, which sometimes creep exten- 
sively beneath the soil, and have, more or less, the appearance of thick fleshy roots. The roots 
of the spru’ious Ferns consist of thick straight rigid fibres. 
The stems, or rhizomes, assume two perfectly distinct forms. In some Ferns, as already 
intimated, they creep extensively either beneath or upon the surface of the soil, or over the 
rock or trunk which supports them. These throw up their fronds at intervals, the growing 
point of the stem being in advance of the youngest fronds, and the fronds themselves being 
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