166 
IX. ASl'LEXI I' 31. 
tinct, sending off simple or forked vennles, which seldom 
reach the margin : when forked, the forking is either be- 
yond or opposite to the fructifications. Each sorus is linear, 
and at first covered by a narrow lanceolate membranous 
indusimn, which has a jagged or crenate margin ; this is 
soon pushed aside by the spore-cases, which not unfre- 
quently become confluent over the under surface. The fruc- 
tification is mature about August. 
This species occurs, not very 
commonly, in the mountainous 
rocky districts of England, Wales, 
and Scotland, and less commonly 
in Ireland, delighting in the vi- 
cinity of waterfalls- It is found 
throughout the alpine and sub- 
alpine districts of Europe. 
This is usually a free growing 
plant under cultivation, not, how- 
ever, often attaining the size 
which it acquires in sheltered 
places amongst the moistened 
rocks, in the interstices of which 
its roots delight to insinuate 
themselves, often so firmly as to 
render it next to impossible to 
extricate the plants uninjured. 
It requires well drained pots, and 
soil intermixed plentifully with 
small lamps of broken freestone, 
and delights in a damp shsdy [Aspk-nimn 
situation, provided the moisture is not too nearly stagnant. In 
the rockery it needs shade and the shelter of a befl-giaas, 
to protect it from the hot arid summer air, and the 
excessive wet of winter, which seldom drains away suffi- 
ciently from artificial rock work- The proper liTI ftlirr~ 
for these half-hardy ferns, are those having a small 
penag in the crown, which may be closed or not at 
