were inflected.
The result was widely different when bits of meat were placed in a
medial line at the distal or proximal ends of the disc. In three of the
seventeen experiments thus made, owing either to the state of the leaf
or to the smallness of the bit of meat, only the immediately adjoining
tentacles were affected; but in the other fourteen cases the tentacles
at the opposite end of the leaf were inflected, though these were as
distant from where the meat lay as were those on one side of the disc
from the meat on the opposite side. In some of the present cases the
tentacles on the sides were not at all affected, or in a less degree,
or after a longer interval of time, than those at the opposite end. One
set of experiments is worth giving in fuller detail. Cubes of meat, not
quite so small as those usually employed, were placed on one side of
the discs of four leaves, and cubes of the same size at the proximal or
distal end of four other leaves. Now, when these two sets of leaves
were compared after an interval of 24 hrs., they presented a striking
difference. Those having the cubes on one side were very slightly
affected on the opposite side; whereas those with the cubes at either
end had almost every tentacle at the opposite end, even the marginal
ones, closely inflected. After 48 hrs. the contrast in the state of the
two sets was still great; yet those with the meat on one side now had
their discal and submarginal tentacles on the opposite side somewhat
inflected, this being due to the large size of the cubes. Finally we
may conclude from these thirty-five experiments, not to mention the six
or seven previous ones, that the motor impulse is transmitted from any
single gland [page 240] or small group of glands through the blade to
the other tentacles more readily and effectually in a longitudinal than
in a transverse direction.
As long as the glands remain excited, and this may last for many days,
even for eleven, as when in contact with phosphate of lime, they
continue to transmit a motor impulse to the basal and bending parts of
their own pedicels, for otherwise they would re-expand. The great
difference in the length of time during which tentacles remain
inflected over inorganic objects, and over objects of the same size
containing soluble nitrogenous matter, proves the same fact. But the
intensity of the impulse transmitted from an excited gland, which has
begun to pour forth its acid secretion and is at the same time
absorbing, seems to be very small compared with that which it transmits
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