THE WOOD FERNS. 145 
the disposition of certain specimens. Generally speak- 
ing, it may be said that the variety ixtermedium is 
rather longer, narrower and more finely cut than the 
type, with the under surface minutely glandular. The 
young fronds are frequently so sticky from these glands 
that they adhere wm 
to the paper when 
pressed for the her- 
barium. It is our 
commonest form 
and is abundant in 
nearly all moist 
woods. The vari- 
ety dilatatum is an os 
upland or moun- A PINNULE. Much enlarged. 
tain form, at least inthe southern part of its range. It 
is more inclined to be ovate and the inferior pinnules 
on the lowest pair of pinnz are conspicuously elongated. 
The principal points that are depended upon for separat- 
ing the forms may be contrasted as follows :— 
In true spzvulosum the scales of the stipe are pale brown, 
the blade ovate-lanceolate, the pinnz oblique to the 
rachis and the indusium glabrous. 
In the variety zztermedium the scales of the stipe are 
brown with a darker centre, the blades oblong-ovate, 
often rather narrow, the pinne spreading, the indusium 
ragged edged and dotted with stalked glands. 
In the variety dilatatuim the scales of the stipe are 
larger, brown with a dark centre, the blade broadly 
ovate, the lower pinnules much lengthened and the 
indusium glabrous. 
It may be noted in passing that in Great Britain where 
adilatatum is common, and frequently regarded as a dis- 
