BRITISH FERNS. 
INTRODUCTION. 
A Febn is a flowerless plant which has a fibrous root, vascular 
stem, nerved leaves, reticulated epidermis furnished with stomata ; 
and which bears spores as fruit in capsular receptacles. 
The Ferns and their Allies form the first order of the Linnean 
class Cryptogamia, and the structure of them shows so exactly an 
intermediate character between the Phanerogamia and Cellulares, that 
all systems of classification have assigned them this station among 
vegetables. They are without flowers containing stamens and pistils 
and producing true seeds : they therefore cannot with propriety be 
arranged with Pheenogamous plants ; while their vascular texture and 
fully-developed leaves, borne upon a true stem, show their organi- 
zation to be greatly above that of any other families of Cryptogamia. 
Although the Tree Ferns have some analogy with the Cycadeae 
in their habit of growth, the connexion between these and other 
orders is more apparent in the Pteroides or Fern Allies, particularly 
the Equisetaceae and Lycopodiaceae. The Equisetaceae are nearly 
connected with several orders of Flowering plants. In their hollow, 
jointed, siliceous stems, they resemble the Grasses; in other respects, 
the Coniferae and Amentaceae, approaching the latter by means 
of the genus Casuarina, and the former by that of Ephedra; nor 
are they far removed in structure from tlieCharas; thus connecting 
also the Ferns and the Algae. The Lycopodiaceae were considered 
by the earlier botanists as Mosses, but they differ from that tribe, 
not only in habit, but in many important characteristics, especially 
in the fructification, which bears an analogy to that of the Coniferae. 
Thus the tribes under consideration, which are divided according 
to the modern system into Filicales, Equisetales, and Lycopo- 
uiALES — the first the true Ferns, the others the Pteroids or Fern 
Allies, — altogether form valuable, because well-connecting links in 
the great chain of nature. 
