Experiments with these minute sections are not uni formly attended with success. Large shreds perish, and the small ones must be severed clean off. Besides, they require constant supplies of sea water, and unremitting attention to keep it fresh and pure. The vigour of all actinix, indeed, both old and young, seems chiefly to depend on frequent supplies of water. A single shred often produced several anemones, which sometimes re main connected, and become monsters, though common ly detaching themselves asunder.
Actinix frequently change the skin. The colour then appears clearer, and somewhat lighter. We apprehend that all darken with age ; and it is known that some arc of a different hue in autumn and winter, from what they exhibit in spring and summer.
Actinix die when kept in fresh water, they scarcely move, and their brilliant colours fade. They can bear the cold of congelation with impunity ; but the exact degree of cold destructive to them is not yet ascertain ed. From several cruel experiments, it appears that, they suffer pain from 95 to of heat, and lose their hold at 115°. Encreasing it still further, destroys them. When dying from disease, they grow flaccid, contracted, unable to inflate themselves, and gradually waste away. Sometimes, repeated supplies of water will protract life, and infuse vigour into them ; and their death and dissolution are evidently accelerated without it. It is said that these animals suffer nothing from a vacuum ; and that they neither close on the exhaustion of the air, nor open on returning it.
Monstrous actinix are sometimes found in their na tive element ; whose monstrosity commonly consists in a superabundance of parts. We have seen one com posed of two bases under the ring of tentacula, but so situated, that both could not at the same time be em ployed in such a manner as to attach the actinix. The
tentacula were as numerous as if they had belonged to two separate animals of that particular species. Four of these, by a greater degree of monstrosity, diverged from one root. The abbe Dicquemare instances other monstrosities, such as a perfect body and basis diverging into two branches, each provided with the natural num ber and proportions of tentacula. Some authors seem disposed to ascribe the facility of reproduction, and also the monstrosities of the actinic:, to their gelatinous structure. The constituent parts, they conceive, may r}tffer greater hajury without destruction, and may di erge from the laws restraining them within certain hounds and proportions, owing to their softness and flexibility. But it is difficult to assent to this theory, from our knowledge or the extraordinary reproductions that ensue in other animals, whose substance and contexture by no means come within the description of gelatinous, at least when they are in a mature state.
The anatomical structure of the actinix is little un derstood. Cuvier observes, that nothing resembling nerves is to be found in them, yet they possess a deli cate sense of feeling ; and although eyes seem entirely wanting, they are sensible' of the presence of light, which, in general, seems to produce some agreeable sensation. We cannot explain by what means their powerful adhesion is occasioned; whether or not it is simply by exclusion of the surrounding fluid ; nor do e know how the tentacula retain their prey ; whether it be by some means analogous, or by a gelatinous substance of a peculiar nature.
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