glands on different parts of the leaf transmit their motor power in a
somewhat different manner. If a bit of meat be placed on the
long-headed gland of a marginal tentacle, it quickly transmits an
impulse to its own bending portion; but never, as far as I have
observed, to the adjoining tentacles; for these are not affected until
the meat has been carried to the central glands, which then radiate
forth their conjoint impulse on all sides. On four occasions leaves
were prepared by removing some days previously all the glands from the
centre, so that these could not be excited by the bits of meat brought
to them by the inflection of the marginal tentacles; and now these
marginal tentacles re-expanded after a time without any other tentacle
being affected. Other leaves were similarly prepared, and bits of meat
were placed on the glands of two tentacles in the third row from the
outside, and on the glands of two tentacles in the fifth row. In these
four cases the impulse was sent in the first place laterally, that is,
in the same concentric row of tentacles, and then towards the centre;
but not centrifugally, or towards the exterior tentacles. In one of
these cases only a single tentacle on each side of the one with meat
was affected. In the three other cases, from half a dozen to a dozen
tentacles, both laterally and towards the centre, were well inflected
or sub-inflected. Lastly, in [page 236] ten other experiments, minute
bits of meat were placed on a single gland or on two glands in the
centre of the disc. In order that no other glands should touch the
meat, through the inflection of the closely adjoining short tentacles,
about half a dozen glands had been previously removed round the
selected ones. On eight of these leaves from sixteen to twenty-five of
the short surrounding tentacles were inflected in the course of one or
two days; so that the motor impulse radiating from one or two of the
discal glands is able to produce this much effect. The tentacles which
had been removed are included in the above numbers; for, from standing
so close, they would certainly have been affected. On the two remaining
leaves, almost all the short tentacles on the disc were inflected. With
a more powerful stimulus than meat, namely a little phosphate of lime
moistened with saliva, I have seen the inflection spread still farther
from a single gland thus treated; but even in this case the three or
four outer rows of tentacles were not affected. From these experiments
it appears that the impulse from a single gland on the disc acts on a
greater number of tentacles than that from a gland of one of the
exterior elongated tentacles; and this probably follows, at least in
part, from the impulse having to travel a very short distance down the
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