
118 THE BRITISH FERNS. 
from their pure and airy habitats, are liable to TZ of 
suffocation from too close confinement. 
The species, like others of similar habit, may be increased by 
division of the crowns. 
The varieties of this kind of Spleenwort are not numerous; the 
following only, which are not very strongly marked, are known 
to us :— 
1. multifidum (Woll.). This is bifidly or multifidly divided 
towards the apex of the frond, and is rather more lax than the 
normal state of the species. It is almost as frequent in some 
localities as the normal form, and sub-permanent under cultiva- 
tion. We have it in a characteristic state from— Yorkshire: Settle, 
A. Clapham. Westmoreland: Whitbarrow, R. Morris. Carnar- 
vonshire: Llanberris, Dr. Allchin. 
2. bipinnatum (Qlowes). The pinnæ of this variety are deeply 
incised, very much as in Asplenium Trichomanes incisum. It was 
found on Whitbarrow, 1n Westmoreland, by Mr. I. Hudhart, in 1853, 
and was in the possession of Mr. Clowes, of Windermere. 
9. incisum (M.). This form seems to be generally of free growth, 
the specimens being from six to nine inches high. The pinne are 
oblong or trapeziform, and the margin is deeply cut into bluntish 
teeth, instead of being erenated, as in the more characteristic form 
of the species. It is probably a not uncommon form, as we have 
seen it from various localities :—Carnarvonshire, J. Atkins ; Crosby 
Ravensworth, R. Clarke; Whitbarrow, R. Morris; Drummond 
Hill, Perthshire, C. M‘Intosh. 
4. acutifolium (Gibs.). The pinne of this form, which was found 
by the late Mr. S. Gibson, are lanceolate and acute, EM to 
Mr. Newman, whose brief account is all we know of it. 

