240 
ASPLENIACE^. 
The midvein of the pinnules is waved, the lateral veins are 
forked shortly after leaving the midvein, and the anterior branch 
of each bears on its side, about midway between the midvein and 
margin, a linear cluster of capsules, as already described : the 
anterior free edge of the involucre is split into a series of capil- 
lary segments. The frond is extremely tender and fragile, and 
withers almost immediately on being gathered. 
The forms of this fern are so well marked and distinct, that 
some of the best continental botanists have not hesitated to give 
them as distinct species. i 
Linneus considered them as constituting two species : — Po- 
lypodium rhcBticumy which he described as having bipinnate 
fronds, with the leaflets and pinnaB remote and lanceolate, and 
their serratures acuminate ; ” * and Polypodium Filix-femina, 
“with bipinnate fronds, and acute, pinnatifid and lanceolate pin- 
nules.” t Whatever we may have heard in praise of the Lin- 
nean characters, I confess that to me they are very often far from 
satisfactory, and the only inference to be drawn from those I 
have now quoted, coupled with the existence of authentic re- 
presentatives of each species in the Linnean herbarium, is this : 
that Linneus regarded as two species that family (so to speak) 
of ferns, which in Britain, as well as on the continent, we usu- 
ally designate by the name of Filix-femina. 
To these Schreber added a third, under the name of Polypo- 
dium molle, which is described as having the fronds sub-bipin- 
nate, the pinnules lanceolate, somewhat obtuse and crenulate at 
the apex.J This form, as well as some of the others, is describ- 
ed by Weiss, but only as a variety of Filix-femina. And the 
enquiry, even restricted to those authors who treat the forms as 
species, is sufficiently voluminous without any reference to others 
who have considered them varieties. 
* Polypodium rhceticum frondibiis bipinnatis : foliolis pinnisque remotis lan- 
ceolatis : serraturis acuminatis. — Species Plantarum, 1552. 
t Polypodium Filix-femina frondibus bipinnatis : pinnulis lanceolatis pinna- 
tifidis acutis. — 1. c. 1551. 
I Polypodium molle frondibus subbipinnatis ; pinnulis lanceolatis, obtusius- 
culis apice crenulatis.—Schreber, Spic. Flor. Lips. p. 70, as quoted by Roth. 
