THE ALPINE POLYPODY. 
never to occur in company with the more perfect sori, but only where the spore-cases are much fewer in 
number than usual, "Tous they 
jad the appear 
псе of lacerated membranaceo-filamentous expansions 
of those points of the veins which formed the recep 
Jes ; and they appeared to arise from some 
normal 
condition, which had limited the power of producing spore-cases to the side or base of the receptacle, 
lile on the upper side the cells of the receptacle had been directly prolonged into the indusioid 
membrane ; but in no ease have we seen what could be considered as a true 
ndusium, On the other hand, 
Mr. Rylands, of Warrington, who. 
ards the plant as an Athyrium, has communicated the result of some 
observations made in 1855, in company with Mr. Wilson, from which the fo 
passages aro quoted : 
— In those sori which are largo and fully ripe, the indusium could not be seen, though I imagine 
dissection would show traces of it. One sorus was found still close 
the spore-cases little developed ; 
niform, and lay alongside the venule. In many of the smaller sori remains of an indusium 
and in two or three it was as nearly perfect as one may expect to find it, ‘The ша 
laciniated with fine projecting points. ‘The laciniatod margins are produced by the rupture of the 
cuticle, and the fine points are the cell-walls thereof. ‘The indusium is very tender, shrivels, and where 
r than in 
the spore-eases are numerous, is speedily concealed or perhaps displaced by them: it is sm: 
the other forms of Athyrium. These peculiarities seem to result from the rupture of the cuticle taking 
place ca 
in the progress of development of the sori ; but that it has the true indusium of an Athyrium 
Think cannot be further disputed.” Subsequently, Mr. Rylands writes :— Tho ‘indusia’ of alpestre 
are not, I think, confined to the imperfect sori, though after bursti 
ig they soon shrivel а 
the larger ones. I have compared it with A. Filir,famina molle, and though in t 
exture, position, 
and general character, there was littlo difference, I am compelled to admit that in the ease of alpestre 
the spore-cases seemed to lie within the proper cuticle of the frond, while the evidence of a distinct 
much clearer in molle. This supports your view to some extent; but, all things 
considered, is it suflicient to remove the plant from others so evidently its allies?” When so many of 
the sori—not only the majority, but all, with few exceptions, and those exceptions havi 
strongly 
marked imperfect ог. 
normal el 
aractors—really appear to be the round naked masses of Polypodium, 
we have no alternative, repudiating as we do the other grounds of sepa 
ation already adverted to, but 
to retain this plant in that genus, 
he Flexil 
Polypody—P. atpesmer rurxine—(Piare VIL, в. к) as communicated to us by Mr. 
Backhouse, is certainly a very distinct variety, and may b ner be 
species, the ing the view adopted 
by its only discoverer, Mr. Backhouse, who writes :—" Dissimilar as it is from P. alpestre, 1 shall 
continue doubtful of its specific dif 
nee if it does not turn up in other places.” It differs in being 
more slender and flaccid ; in having a much narrower outline, and consequently shorter pinne, with a 
‚er of pinnules; in the form of the pis 
nules, which are oblong, narrowed below, 
sessile or adnate, and distantly toothed ; in the very short stipes, becoming obsolete in the cultivated 
plants ; and in a tendency to bear perfect sori at the base of the frond, while the apex is barren—the 
reverse of what usually happens. ‘The absence of stipes, which Mr. Newman 
icludes in his definition. 
is not constant, the wild specimens sent by Mr. Backhouse having a distinct stipes of about a couple of 
inches; this part, however, is always very short. ‘The fronds are from six or seven to twelve or 
hteen inches in length ; the pinnae, spreading or more or less deflexed, short, with about six or eight 
pairs of pinnules, ‘The sori are few, six or eight on a pinnule, usual 
y distinct. In the cultivated plant 
the clusters are very numerous in the lower half, a 
d scarcely extend upwards beyond the middle of 
the frond ; but this character is not constant, one frond communicated by Mr. Clapham, and the wild 
fronds from Mr. Backhouse, be 
frueti 
| throughout, and another obligingly forwarded by Mr 
ied, 
hed to the side of the vein, and the sori were 
Newman being fertile both at the base and apex. In this latter, which was only sparingly fructified, 
the spore-eases appeared for the most part to be at 
slightly clongated rather than circular, indicating an affinity with Athyrium, and there was in some 
cases a peculiar membr 
ous development in the position of an indusium, again indicating 
