Insectivorous Plants eBook

This eBook from the Gutenberg Project consists of approximately 527 pages of information about Insectivorous Plants.

Insectivorous Plants eBook

This eBook from the Gutenberg Project consists of approximately 527 pages of information about Insectivorous Plants.

Now for the general results.  Of the eighteen leaves on which bits of meat were placed on the right or left sides of the disc, eight had a vast number of tentacles inflected on the same side, and in four of them the blade itself on this side was likewise inflected; whereas not a single tentacle nor the blade was affected on the opposite side.  These leaves presented a very curious appearance, as if only the inflected side was active, and the other paralysed.  In the remaining ten cases, a few tentacles became inflected beyond the medial line, on the side opposite to that where the meat lay; but, in some of these cases, only at the proximal or distal ends of the leaves.  The inflection on the opposite side always occurred considerably after that on the same side, and in one instance not until the fourth day.  We have also seen [page 239] with No. 5 that bits of meat had to be added thrice before all the short tentacles on the opposite side of the disc 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.

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Insectivorous Plants from Project Gutenberg. Public domain.