86 FERNS OP GREAT BRITAIN, 



and beautiful, of a delicate and tender green, quivering 

 before the rough winds, but of too firm a texture to be 

 stirred by a light summer's breeze. The frond is long 

 and narrow, tapering and acute at its upper end, and 

 again gradually lowering at the base, when it becomes 

 very distinctly heart-shaped. Its margin is entire and 

 waved, the leafy portion being placed on a short and 

 shaggy stalk, which is of a purplish brown colour at the 

 base. While the frond is young, it has a downy or cot- 

 tony substance on its under side, and often also on each 

 side of the midrib on its upper surface. The length of 

 a full-grown frond is from six inches to a foot and a half. 

 It grows very luxuriantly on stone walls, at the borders 

 of streams, or the sides of wells, and is sometimes 

 found in mines or caverns. Sir J. E. Smith says of its 

 fronds, " In the now open vault by the great hall in 

 Conway Castle, I have gathered them upwards of three 

 feet long, and nearly five inches wide." Sir W. J. Hooker 

 found them in the moat at Kenilworth Castle more than 

 two feet long. A very stout and strong midrib runs 

 through the leafy part, from which forked veins arise, 

 the smaller veins being parallel to each other, and ruU' 

 ning towards the margin, but ending just within it. 

 Oblong clusters of fructification, some long and some 

 short. He in the direction of the veins, at short intervals, 

 on the upper part of the leaf, occupying about two- 

 thirds of its length. They are placed in oblique parallel 

 lines on each side of the mid-vein, and when seen in their 

 ripened state seem to be single. If these are examined 

 when young, they may however be seen to be composed 

 of two distinct patches, facing each other, and divided 



