9HMKJM - The Complete Work of Charles Darwin Online

311 DARWINIANA. -
The operation of this fly-catching apparatus, in
any case, is plain. If the insect
alights upon the disk
of the leaf, the viscid secretion holds it fast— at least,
an ordinary fly is unable to escape — its struggles only
increase the number of glands involved and the
amount of excitement ; this is telegraphed to the sur-
rounding and successively longer tentacles, which
bend over in succession, so that within ten to thirty
hours, if the leaf is active and the fly large enough,
every one of the glands (on the average, nearly two
hundred in number) will be found applied to the body
of the insect. If the insect is small, and the lodgment
toward one side, only the neighboring tentacles
may take part in the capture. If two or three of
the strong marginal tentacles are first encountered,
their prompt inflection carries the intruder to the
centre, and presses it down upon the glands which
thickly pave the floor; these notify all the surrounding
tentacles of the capture, that they may share the
spoil, and the fate of that victim is even as of the first.
A bit of meat or a crushed insect is treated in the
same way.
This language implies that the animal matter is in
some way or other discerned by the tentacles, and is
appropriated. Formerly there was only a presumption
of this, on the general ground that such an organization
could hardly be purposeless. Yet, while such
expressions were natural, if not unavoidable, they
generally were used by those familiar with the facts
in a half-serious, half-metaphorical sense. Thanks to
Mr. Darwin's investigations, they may now be used in
simplicity and seriousness.