254 
HISTORY OF BRITISH FERNS 
becoming elevated on a short stalk. The scales are from 
forty to fifty in number, and are of a pale-brown colour, 
bearing numerous whitish spore-cases. 
The branched fertile stems have their sheaths smaller 
than the simple fertile ones, but larger than the barren 
ones. Several of the uppermost joints produce whorls of 
branches, and the stem is terminated by a cone of fructi¬ 
fication. In these cases, however, the number of branches 
is less than that produced by the ordinary barren stems, 
and the cone is smaller than those produced by the ordinary 
fertile stems. 
The section of the stem of this species is very different 
from that of any other, though having most resemblance to 
those of E. arvense and E. sylvaticum. The exterior shows 
a series of sharp ridges with angular furrows; the central 
cavity rather exceeds a third of the whole diameter ; the 
cylinder of the stem is then pierced by three circles of 
cavities—one of longish oblong openings opposite the 
furrows, one of minute pores exterior to these and opposite 
the ridges, and another of minute pores on their inner side 
also opposite the ridges. 
Probably this species is tolerably plentiful in moist shady 
woods, which are the situations it affects ; but it has as yet 
