The leaves arise from an almost woody axis; they [page 333] are linear,
much attenuated towards their tips, and several inches in length. The
upper surface is concave, the lower convex, with a narrow channel down
the middle. Both surfaces, with the exception of the channel, are
covered with glands, supported on pedicels and arranged in irregular
longitudinal rows. These organs I shall call tentacles, from their
close resemblance to those of Drosera, though they have no power of
movement. Those on the same leaf differ much in length. The glands also
differ in size, and are of a bright pink or of a purple colour; their
upper surfaces are convex, and the lower flat or even concave, so that
they resemble miniature mushrooms in appearance. They are formed of two
(as I believe) layers of delicate angular cells, enclosing eight or ten
larger cells with thicker, zigzag walls. Within these larger cells
there are others marked by spiral lines, and apparently connected with
the spiral vessels which run up the green multi-cellular pedicels. The
glands secrete large drops of viscid secretion. Other glands, having
the same general appearance, are found on the flower-peduncles and
calyx.
FIG. 14. (Drosophyllum lusitanicum.) Part of leaf, enlarged seven
times, showing lower surface.
Besides the glands which are borne on longer or shorter pedicels, there
are numerous ones, both on the upper and lower surfaces of the leaves,
so small as to be scarcely visible to the naked eye. They are
colourless and almost sessile, either circular or oval in outline; the
latter occurring chiefly on the backs of the leaves (fig. 14).
Internally they have exactly the same structure as the larger glands
which are supported on pedicels; [page 334] and indeed the two sets
almost graduate into one another. But the sessile glands differ in one
important respect, for they never secrete spontaneously, as far as I
have seen, though I have examined them under a high power on a hot day,
whilst the glands on pedicels were secreting copiously. Nevertheless,
if little bits of damp albumen or fibrin are placed on these sessile
glands, they begin after a time to secrete, in the same manner as do
the glands of Dionaea when similarly treated. When they were merely
rubbed with a bit of raw meat, I believe that they likewise secreted.
Both the sessile glands and the taller ones on pedicels have the power
of rapidly absorbing nitrogenous matter.
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