THE FILMY FERNS. 
147 
peculiar spore-vessel of this species, and its place of attach- 
ment. It frequents precisely the same haunts as the Tunbridge 
Fig. 33.— The One-sided Filmy Fern {Hymenophyllum unilaterale), showing 
Habit, and detached Pinna with Involucre. 
Fern, but is, perhaps, a trifle more common. The fronds are 
not unfrequently forked, but no symmetrical variety has yet 
been found. 
The Killarney Fern 
{Trichomanes radicans). 
This is, undoubtedly, the king of the Filmy Ferns of Britain, 
and, in point of fact, can claim a foremost place amongst 
those of the world generally, rivalling the best in bold growth 
and delicate beauty. The fronds, which are roughly triangular 
in shape, grow, under favourable conditions, to over 1ft. in length, 
of which from a third to one-half will constitute the stalk; 
they are beautifully divided, the pinnulets being deeply cut. 
The colour is a delicate green, and the texture tough, though the 
L 2 
