






THE COMMON MAIDENHAIR SPLEENWORT. 109 
of brick, rock, or mortar, and the interstices only filled with finer 
soil, consisting of the same ingredients, pounded or broken up, and 
mixed with a due proportion of sandy loam. 
This peculiar mode of potting is suitable especially for the present 
species, the Wall Rue, and the Ceterach. None of these plants, 
moreover, require so much shade as other Ferns, although, if they 
are kept tolerably dry at the crown, they do not refuse to grow in 
structures which are shaded for other kinds. Water must be applied 
cautiously; the crowns or centres of growth should not be wetted, 
and the fronds themselves are the better for being kept dry, although 
an occasional syringing, if necessary to cleanse them, will not be found 
injurious, provided the fronds and the crown are afterwards allowed. 
to get dry. The more successful instances we have seen of the 
cultivation of this Fern, were in cases in which the atmosphere of 
the greenhouse was kept rather drier than is usual in structures 
devoted to Fern culture, 
Until lately very little variation had been observed in this species. 
Besides incisum, there had been found plants in which the apex of 
the frond was dichotomously divided, but as often occurs in other 
species, these have proved inconstant. There are now, however, 
several well-marked varieties known :— 
1. incisum (M.). This is the most beautiful variety yet discovered, 
and is exactly analogous to the var. cambricum of Polypodium vulgare. 
The fronds are of the usual outline, pinnate. The pinne have a 
tendency to become triangular, and in some of the best forms of the 
variety are nearly uniformly so, with acute apices; they are deeply 
pinnatifid, the segments narrow oblong or elliptic, usually acute, and 
irregularly sometimes deeply serrated, the larger ones not unfre- 
quently lobate. It has been found in several localities, namely— 
Devonshire, Rev. W. S. Hore. Lancashire: Kant Clough, near 
Burnley, S. Gibson. Yorkshire : Smeerset, near Settle, J. Tatham, 
A. Clapham. Cumberland: Borrowdale, Miss Wright. ? Clare, J. 
R. Kinahan. Jersey, Sherard, according to Plukenet. The Settle 
form, as communicated to us from Mr. Clapham's garden, is the 
finest we have seen. In this the more perfect pinne sometimes 

