=e 
THE FERNS OF NORTH-WESTERN IND/A. 461 
DistTRiB.— Asia: Afghan.; N. Ind.(Him.)Sikkim, rare. Assam—Khbasi Hills 3-4000’, 
Mann ; Manipur, Watt. Rajputana—Mt. Abu, King. Afr. : Abyssinia—Schimper. 
In the north-east of India, where it is rare, this fern grows larger than in the 
north-west. Some specimens I have, or have seen, collected by Gamble and 
Levinge, are so different from others, and from the north-west plant that 
a variety-monger might make one here. One plant has fronds 11 
inches long by 24 inches broad, with hardly any stipe. A frond on 
another sheet is 1 foot long by 2 inches broad, and stipe 2 inches, The cutting 
of these is very coarse, the segments being broader and blunter than usual, and 
sometimes sub-crenulated or sub-lobed round the ends of the veins. There is a 
distinct hyaline: (or cartilaginous) margin, which is rarely distinguished in my 
North-Western specimens. And on some small plants with similar cutting the 
sori are very short and broad. The large specimens seem to bear the same 
relation to the N.-W. India form that A. awrewm of the Canary Islands bears to 
A, ceterach of North Europe ; but intermediate forms might perhaps be picked 
out, Assam plants of A. alternans, in the Calcutta Herbarium, are like those 
from Sikkim, and the sori are more apical than those of N.-W. Indian plants. 
Colonel Beddome says—of the venation and fructification—“ veins sub-flabel- 
late, all free ; sori copious on all the lobes in two rows, linear-oblong, erect- 
patent, the superior basal one parallel with the costa ”— parallel with the rhachis 
of the frond, I presume he means : but his enlarged drawing, while showing the 
venation fairly, does not show the basal sori he mentions ; and it seems to show 
that the veins in the decurrent base of the segments spring from the rhachis of 
the frond and not from the costa of the segment or lobe. This they sometimes 
appear to do; but the substance of the frond is thick and opaque, and it is net: 
always easy to trace the basal veins to their origin, The position of the sori 
depends of course upon the direction of the veins. The segments or lobes are 
more gradually decurrent on the rhachis on the superior side than on the 
inferior, and a main branch from the costa runs off, on the superior side, 
parallel to the rhachis from near the base of the costa, so near in some cases 
that the off-take is obscure ; and it gives off veinlets towards the margin. 
This branch and its veinlets are not generally soriferous, and in the lower half 
of the frond perhaps never so, and then all the sori appear to lie in the seg- 
ments, and at an angle with the costa of the segment, Higher up the frond 
basal sori appear, both on the parallel branch vein and on the veinlets which 
spring from it, and towards the apex of the frond the involucres of the long 
parallel basal sori open towards the rhachis of the frond, instead of towards 
the costa of the segment as the segmental sori do, At the apex of the frond, 
as the segments become confluent, the rhachis becomes the costa of the apex, 
and the involucres open inwards towards it. 
