260 
THE FERN WORLD 
vulgare — start a number of delicate-looking, pale-green 
fronds reaching a length of from six to twenty inches. The 
frond has a long stipes, pale green, slender, and brittle, and 
generally double the length of its leafy portion, which is 
triangular in form. Arranged in pairs on each side of the 
rachis are long tapering pinnae. The lowest pair is usually 
the longest, and succeeding pairs become shorter and shorter, 
until they are merged in the apex of the frond. The two 
or three basal pairs are, usually, distinctly pinnate, being- 
attached to the rachis by the whole width of their bases. 
But above these lower pairs the pinnae are run together by a 
sort of leafy wing, which connects them with the pinnae 
above and below them. The basal pinnae are again partially 
divided into blunt-pointed lobes or segments, the indentation 
forming the lobes being deeply cut in, but not extending 
quite down to the mid-stems of the pinnae; the clefts being, 
however, deepest in the middle of the lowest pairs of pinnae, 
and becoming gradually less towards the apices of the latter 
— which are somewhat sharp pointed — until they disappear 
in the leafy tips. The venation consists of wavy mid-veins 
running down the lobes of the pinnae, with venules branching 
off from them on each side towards the lobe margins, the 
venules being sometimes simple and sometimes forked, and 
bearing at their extremities the circular heaps of uncovered 
or non-indusiate spore cases. The fructification is thus 
what is called marginal or nearly so, the sori extending in 
little lines on each side of the mid-veins of the lobes, but 
not proceeding quite to the apices of the latter. Nearly 
the whole under side of the frond is covered with the 
fructification. 
Two peculiarities about this Fern must be noticed. The 
upper pinnae on the fronds are narrowly lance-shaped, 
broadest at their bases, and tapering to their apices. But 
in the lowest pairs of pinnae the latter taper somewhat also 
