THE HARTSTONGUE 
193 
tufted rootstock, tlie crown of which is slightly elevated 
above the surface of the soil. Large plants produce a great 
number of fronds. The maximum length of the latter, in- 
cluding stipes and leafy portion, is usually stated to be two 
feet. But we have ourselves seen fronds of this handsome 
Fern three feet long, and we believe it possible that this 
length may he exceeded even in these Islands when the 
Hartstongue is growing under conditions peculiarly adapted 
to its development. When growing on walls, the fronds are 
sometimes only an inch or two in length when fully developed ; 
and they vary from this length to three feet, according 
to the situation of the plant. The stipes is generally 
about one -third the length of the entire frond. The leafy 
portion of the latter in its normal form is simple or undivided 
and tongue-shaped, tapering to a point at its apex, widest at 
the centre, narrowing towards its base, hut again expanding 
into a kind of ear-shaped projection on each side of the rachis 
where the latter commences. The base of the leafy portion 
of the frond is thus hollowed upwards on each side of the 
rachis. The fronds are usually a rich shining green, smooth 
and leathery. A very distinct feature is the rachis or mid- 
rib, which is carried up in continuation of the stipes, from 
the base to the apex of the leafy portion of the frond. It is 
thick and elevated into a kind of ridge. From each side of 
it run towards the margin of the frond, a series of free veins 
once or twice forked. The term ‘ free ’ as applied to a vein, 
indicates that after it leaves the mid-rib — however much it 
may itself become forked— it does not run into any neigh- 
bouring veins, but proceeds £ free ’ to the margin of the frond. 
The veins run closely together, taking a somewhat oblique — 
upward — direction. Their arrangement — a very beautiful 
one — can be clearly seen by placing the frond against the 
light. Upon certain of them on each side of the rachis, at 
the back of the frond, and generally at intervals of about the 
