








62 THE BRITISH FERNS. 
summer, or the necessary supply of moisture must be applied by 
means of syringing. A cool shady Fern house is the proper place 
in which to carry out this mode of culture. The fronds push out 
from the basket on all sides, and have a very pleasing appearance. 
This species may be readily increased by dividing the rhizome. 
There are many deviations from the typical form of this species 
besides those which have been already briefly noticed; but they 
are chiefly of interest to the horticultural enthusiast rather than to 
the botanist; except, indeed, so far as the latter may regard them 
as evidences of the mode and extent of variation to which common 
species are subject, and may hence learn to appreciate rightly the 
differences which are found to exist amongst less familiar exotic 
species. It is, therefore, chiefly for the information of Fern culti- 
vators, most of whom take an especial interest in these variations, 
that they are here enumerated. 
The typical form of the Common Polypody has longish and com- 
paratively narrow fronds. That form of this typical series which 
differs in the least degree, albeit constantly, from the normal state, 
has the ends of its lobes gradually tapering off to a narrow point, 
instead of being equal in width nearly to the end, and there more 
or less blunt. Another modification has the points of the lobes 
acute, but the margins are at the same time deeply notched, the 
notches forming a series of coarse double serratures; in this state, 
which has sometimes a tendency to furcation at the tips of the lobes, 
the sori are not unusually decidedly oblong, a remarkable feature, 
in which respect it somewhat deviates from the generic type. 
Another slightly differing form has the ends of some or all of the 
lobes divided, with the parts spreading, so that the lobes become 
more or less manifestly two-forked ; or occasionally more than two 
points are developed to each lobe, and we have thus an indication 
of the manner in which are formed the tasselled apices which are 
now found to be common among British Ferns, and even occur in 
the present species. 
The fronds, in some forms, moreover, acquire unusual breadth, so 
as to assume a broad oblong or ovate-oblong outline; and this 
departure from the typical outline is occasionally accompanied by 

