8 . 
THE MOUNTAIN PARSLEY FERN. 
-17 / osorus crisp its . 
Plate 5, Figs. 9 and 10, Page 225. 
We have here another Fern which is the only one of its 
genus inhabiting the British Islands — a genus which in- 
cludes Ferns whose spore cases, massed in little round heaps 
at the backs of their fronds, become confluent when fully 
developed, and have no special indusium, but are covered by 
the frond margins, which are turned back over them. The 
Mountain Parsley Fern, as its name indicates, loves rocky 
habitats in mountainous districts, growing, indeed, in such 
localities from the level of the sea to an altitude of three 
thousand five hundred feet above it. It sometimes densely 
covers a considerable space on the mountain sides, its roots 
penetrating the earthy seams in its rocky home, and its 
fronds, adding freshness and beauty by their bright green 
verdure to their surroundings. 
Description. — The generic name, Allosorus, comes from 
two Greek words alios, ‘ various,’ and sorus, ‘ a heap,’ and 
indicates, it is probable, the variation in the clusters of spore 
cases which, at first massed in separate heaps, become, by 
accretion, confluent. Crispus refers to the crisped or some- 
what curled appearance of the barren fronds, which also bear 
a very marked resemblance, at first sight, to a tuft of parsley. 
Hence the common name of this pretty Fern. It grows 
from a thick tufted rootstock, which possesses a great 
