130 FILICES 
their hooded indusm. ‘The plant is now considered as a sub-species of 
C. fragilis. 
4. Mountain Bladder-fern, or Wilson’s Fern (C. montdna).— 
Fronds triangular, thrice pinnate ; pinnules of lower pinn pinnate ; lobes 
pinnatifid, with linear notched segments. This fern, which is of very 
elegant form, is among the rarest of all our British species. It is very 
distinct from the others, and its small triangular very compound fronds are 
from four to six inches high. It has a slender creeping scaly underground 
stem, with dark wiry roots. The stalk is about twice as long as the leafy 
portion of the frond, the pinnz are opposite to each other, and the lower pair 
are much longer than the others ; these gradually diminish in size towards 
the upper part of the frond. This plant is exceedingly frail and delicate, 
almost transparent in texture, and is one of the most compound of our 
British ferns. The lower part of the frond is thrice, and the upper part 
twice pinnate, and it has the peculiarity of having the lower side of the lower 
pinne broader than the uppermost side, and some of the upper branches 
sometimes exhibit this inequality. ‘The lower pinne are divided on the lower 
side into pinnules, which are egg-shaped or lanceolate in form, and these are 
again divided into pinnules, which are egg-shaped or oblong and notched, 
the pinnules on the upper side being of the same form as the secondary 
pinnules of the lower side. In the next pair of branches the lower pinnules 
are similar to the secondary pinnules of the lower branches, and after that 
the parts gradually lessen towards the upper portion of the frond. 
The mid-vein of the pinnule is somewhat winding, giving out alternate 
lateral veins, each of which ends in the part of the margin between two 
notches ; at the back of each side vein is placed the roundish capsule cluster, 
covered by the concave indusium with its jagged edge. The clusters of 
fructification are very numerous and distinct. 
This Bladder-fern is a common plant on many rough and stony grounds 
of other countries, its geographical range being extensive. It was found on 
Ben Lawers, in 1836, by Mr. Wilson, when with Sir W. J. Hooker and 
Professor Graham he visited that spot, and it has since been found in several 
places on the mountains of Perthshire and Forfarshire, but nowhere in great 
abundance. 
8. SPLEENWORT (Aspléniwm). 
1. Green Lanceolate Spleenwort (4. lanceoldétum).—Fronds lanceo- 
late, twice pinnate ; pinnz egg-shaped and lanceolate; pinnules toothed or 
lobed ; clusters of fructification nearly marginal. This is one of the most 
elegant of our British ferns, and one of the few which thrive best near the sea. 
Though not exclusively confined to the sea-coast, it is far more frequent 
there than on inland soils, and at Penzance, in Cornwall, is one of the most 
common plants, springing out of every wall, and being as general on the 
hedge-bank as the primrose. It is abundant at St. Michael’s Mount, but 
nowhere in England grows to so large a size as among the damp rocks of the 
Lizard Point. It is also luxuriant at Torquay, in Devonshire. Sometimes 
this fern, like other plants which frequent the sea-coast, flourishes on high 
mountains, and the botanist has welcomed its green fronds on the heights of 
