Octopuses have many

Usage examples of tentacles.

A similar result followed from an immersion of only 15 minutes in a solution of one part of carbonate of ammonia to 218 of water, and the adjoining cells of the tentacles, on which the papillae were seated, now likewise contained aggregated masses of protoplasm.

Inflection of the exterior tentacles owing to the glands of the disc being excited by repeated touches, or by objects left in contact with them--Difference in the action of bodies yielding and not yielding soluble nitrogenous matter--Inflection of the exterior tentacles directly caused by objects left in contact with their glands--Periods of commencing inflection and of subsequent reexpansion--Extreme minuteness of the particles causing inflection--Action under water--Inflection of the exterior tentacles when their glands are excited by repeated touches--Falling drops of water do not cause inflection.

There is, however, a narrow zone close beneath the glands of the longer tentacles, and a broader zone near their bases, of a green tint.

If the glands on the disc are repeatedly touched or brushed, although no object is left on them, the marginal tentacles curve inwards.

It is a much more remarkable fact that when an object, such as a bit of meat or an insect, is placed on the disc of a leaf, as soon as the surrounding tentacles become considerably inflected, their glands pour forth an increased amount of secretion.

We must therefore conclude that the central glands, when strongly excited, transmit some influence to the glands of the circumferential tentacles, causing them to secrete more copiously.

Not only the tentacles, but the blade of the leaf often, but by no means always, becomes much incurved, when any strongly exciting substance or fluid is placed on the disc.

The whole upper surface is covered with glandbearing filaments, or tentacles, as I shall call them, from their manner of acting.

Glands and summits of the tentacles alone sensitive--Transmission of the motor impulse down the pedicels of the tentacles, and across the blade of the leaf--Aggregation of the protoplasm, a reflex action--First discharge of the motor impulse sudden--Direction of the movements of the tentacles--Motor impulse transmitted through the cellular tissue--Mechanism of the movements--Nature of the motor impulse--Reexpansion of the tentacles.

On a leaf bearing altogether 252 tentacles, the short ones on the disc, having green pedicels, were in number to the longer submarginal and marginal tentacles, having purple pedicels, as nine to sixteen.

Spiral vessels, accompanied by simple vascular tissue, branch off from the vascular bundles in the blade of the leaf, and run up all the tentacles into the glands.

We shall hereafter see that the terminal tentacles of the divided leaves of Roridula are still in an intermediate condition.

I presume that they are actually connected with the spiral vessels which run up the tentacles, for on several occasions the latter were seen to divide into two or three excessively thin branches, which could be traced close up to the spiriferous cells.

Their bases are broader, and besides their own vessels, they receive a fine branch from those which enter the tentacles on each side.

I have repeatedly found that the tentacles remain clasped for a much longer average time over objects which yield soluble nitrogenous matter than over those, whether organic or inorganic, which yield no such matter.