136 
THE PERN FAMILIES OF BRITAIN. 
resemblance to tbe feet of a centipede (Scolopendra), whence 
the botanical name. Its nearest allies are the Spleenworts, from 
which it differs by there being double, instead of single, lines 
of fructification; these face each other, and eventually run 
together when mature, their twin character being thus hidden. 
In many of the varieties the arrangement d la centipede 
is so much interfered with that the resemblance is entirely 
upset, the spores appearing in patches of any shape on the 
edges, and sometimes even on the upper surface of the fronds. 
The extremely simple form of the frond of this species 
would seem, at first sight, to afford very little scope for 
Fig. 28.— Scolopendrium vulgare Kelwayii. 
variation ; but, strange to say, it has yielded forms innumer- 
able, some of them quite peculiar to itself, and of the most 
odd and unexpected nature, as will be seen by the descriptions 
of some amongst the following, which, though hardly beautiful, 
are too curious and too constant in their peculiarities to be 
ignored. Owing to the immense number of varieties, we can 
only give a selection of those with which we are personally 
acquainted, and which embrace the majority of the best known 
forms. The figures in parentheses refer to Plate YII. 
S. V. bimarginato-cordatum (double-margined, heart- 
