SCALY SPLEENWORT. 
301 
make their appearance in May, arrive at maturity in autumn, and 
continue green and vigorous throughout the winter : they are 
always fertile. A small portion of the stem is naked, but beset 
more or less thickly with pointed scales : the form of the frond 
is linear, slightly attenuated below, and deeply pinnatifid ; the 
segments are short, rounded, and sometimes crenate or lobed, 
their position as regards the stem is rather oblique ; their entire 
under surface is densely clothed with brown, pointed, imbricated 
scales, which, when examined under the microscope, are found 
to be very beautifully reticulated. 
The venation and fructification of this fern appear to have 
been greatly misunderstood : even Presl, who lays so great stress 
on these characters, has totally misrepresented them. The late- 
ral veins are few in number, alter- 
nate, and irregularly branched ; the 
branches occasionally anastomose 
before their termination, as repre- 
sented by the figure in the margin : 
the anterior branch of each bears an 
elongate cluster of capsules; these 
are situated about midway between 
the midrib and margin of the pinna : 
the points of their attachment are 
indicated in the figure : the first 
anterior lateral vein usually bears 
two of these clusters of capsules, one on each of its principal 
branches. The capsules are attached to that side of the vein 
which is nearest the median line of the pinnae, and not on the 
back of the vein, in this respect following the formula of the 
other Aspleniacece, and totally differing from that of the Poly- 
podiacece ondi Aspidiacean. It should, however, be observed that 
the capsules seated on the vein nearest the main stem of the 
frond, are placed in a position opposite to that of the rest, and, in 
this instance, the dehiscence of the involucre may be said to take 
place towards the main stem. Immediately adjoining the insertion 
of the capsules, and attached to the back of the vein, is an erect, 
white, membranous involucre, exactly corresponding in length 
with the line of capsules with which it is connected. In a very 
