outer tentacles. In no case was the blade of the leaf, even the
attenuated apex, at all inflected.
On both the upper and lower surface of the blade there are numerous
minute, almost sessile glands, consisting of four, eight, or twelve
cells. On the lower surface they are pale purple, on the upper
greenish. Nearly similar organs occur on the foot-stalks, but they are
smaller and often in a shrivelled condition. The minute glands on the
blade can absorb rapidly: thus, a piece of leaf was immersed in a
solution of one part of carbonate [page 283] of ammonia to 218 of water
(1 gr. to 2 oz.), and in 5 m. they were all so much darkened as to be
almost black, with their contents aggregated. They do not, as far as I
could observe, secrete spontaneously; but in between 2 and 3 hrs. after
a leaf had been rubbed with a bit of raw meat moistened with saliva,
they seemed to be secreting freely; and this conclusion was afterwards
supported by other appearances. They are, therefore, homologous with
the sessile glands hereafter to be described on the leaves of Dionaea
and Drosophyllum. In this latter genus they are associated, as in the
present case, with glands which secrete spontaneously, that is, without
being excited.
Drosera binata presents another and more remarkable peculiarity,
namely, the presence of a few tentacles on the backs of the leaves,
near their margins. These are perfect in structure; spiral vessels run
up their pedicels; their glands are surrounded by drops of viscid
secretion, and they have the power of absorbing. This latter fact was
shown by the glands immediately becoming black, and the protoplasm
aggregated, when a leaf was placed in a little solution of one part of
carbonate of ammonia to 437 of water. These dorsal tentacles are short,
not being nearly so long as the marginal ones on the upper surface;
some of them are so short as almost to graduate into the minute sessile
glands. Their presence, number, and size, vary on different leaves, and
they are arranged rather irregularly. On the back of one leaf I counted
as many as twenty-one along one side.
These dorsal tentacles differ in one important respect from those on
the upper surface, namely, in not possessing any power of movement, in
whatever manner they may be stimulated. Thus, portions of four leaves
were placed at different times in solutions of carbonate of ammonia
(one part to 437 or 218 of water), and all the tentacles on the upper
251