6 
CHAPTER II. 
STRUCTURE. 
A fern is a flowerless plant of vascular tissue, its trunk, 
when it possesses one, increasing from the summit, and 
its seeds or spores germinating from no particular point. 
This description renders it easy for any botanist to re- 
cognize a member of the fern-family, but to general 
observers vascular tissue and acotyledonous spores con- 
vey no obvious notion of the appearance; they must, 
therefore, turn their notice to the under-side of the 
fronds or leaves of the plant under consideration, and if 
they find dusty patches dotting the surface, they may 
at once conclude that the plant is a fern. 
A fern has four parts, each liable to variations and 
modifications: they are these, — 1st, the root; 2nd, the 
caudex ; 3rd, the frond ; 4th, the fructification . 
The root of a fern consists of fibres. These are some- 
times placed at short intervals upon the creeping caudex, 
sometimes singly, or in pairs, and sometimes in clusters, 
or they are situated in more or less dense tufts amid the 
Remains of old fronds near the base of an erect caudex, 
forming an immense mass of roots, and penetrating the 
ground to a considerable distance. In some cases these 
roots are simple, in others they are branched, once, 
