286 
THE FERN PARADISE. 
present. It delights in the spray of waterfalls, 
or to be perched on the damp rocks round which 
the mountain streams rush and roar. In such 
situations it has a wide distribution throughout 
the United Kingdom. The fronds grow from little 
black, wire-like rhizomes, which often become 
densely interlaced with the mosses which grow 
on boulder-tops in mid-stream, or wherever per- 
petual moisture makes moss life predominant. 
They have short wire-like stems, and the leafy 
or filmy portion consists of a series of branched 
veins arranged alternately on each side of the 
rachis. The primary veins are divided into 
veinlets, which are arranged in pairs on each 
side of the primary veins. Each vein, whether 
primary or secondary, is bordered by a narrow, 
filmy, leafy wing. The seeds, when they are 
formed, are placed in little cup-shaped receptacles 
in the angles made by the rachis and the 
primary branches of the frond. The general out- 
line of the latter is somewhat egg-shaped. The 
leafv filaments are of a dull, brownish-green 
colour, and semi-transparent. 
