THE FERN WORLD 
356 
of the sun ; but under such conditions it is stunted in size 
and depauperated in form. Upon the loose stone-work, 
which in a hilly country is often employed to support banks 
skirting the roadways the Black Maidenhair Spleenwort will 
frequently be found in abundance, because such stone- 
work, interseamed with earth, affords, when under the 
shelter of trees above it, the kind of position in which this 
Fern delights to grow. But of all situations, the most con- 
genial to Adiaiitum-nigrum are those afforded by a stony 
hedge-bank, completely draped with the branches of haw- 
tliorne, with holly, furze, or other persistent growth. The 
leaves falling from such hedge-banks into the moist and 
shadowy crevices of the loose stones of which it is built, in 
time add leaf-mould to the loam of the hedge-bank, and to 
the crumbling pieces of the stony superstructure ; and in 
the soil thus formed this fern luxuriates. 
Description. — A tiny thing of an inch in length, when 
growing 011 the sunny side of walls and rocks, Asplenimn 
adiantiivi-nigrum attains a length— stalk and leafy part 
together — of two feet when growing under such congenial 
circumstances as have been described ; and its size varies 
from the two extremes, according to the more or less con- 
genial situation of the plant. The stipes is sometimes less 
in length than the leafy part of the frond. But the leafy 
part and stipes are usually equal in length, though sometimes 
— in the most luxuriant specimens — the stipes is double the 
length of the leafy part. The former is smooth, shining, 
and dark purple in colour, the latter a dark shining green. 
The raehis is green in front, but often purple along about 
half of its under side. The form of the leafy portion is 
triangular, its pinmo alternately ranged along on each side 
of the raehis, also somewhat triangular, and furnished with 
alternately-placed pinnules, which are also somewhat trian- 
gular and alternated, and — in the lower part of the frond, 
