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sidered, and the nature of its food, and the force necessary to prepare it for digestion, it was evidently requisite that it should be defended by a crust sufficient to afford a support, and give effect to its powerful oral apparatus, and yet light enough to yield to the efforts of its motive powers; but as this crust, from its composition and nature, was liable to be crushed by a very slight pressure, it required further means of defence, and with these its Almighty and Beneficent Creator has amply provided it, by covering it, like a hedge-hog, with innumerable spines, varying in length, and capable of various movements. The long ones, when erected, defend it on all sides, both from the attack of enemies and from the effects of accidental pressure, and we may conjecture that when the longer ones are couched to answer any particular purpose, the short ones may come into play, and assist in keeping any pressure from the crust. Perhaps, as in the hedge-hog, the ordinary posture of the longer spines is couchant, and they are only erected when the animal is in motion or under alarm.

The wonderful apparatus which closes the mouth of the common or typical sea-urchin,' is another and striking proof that Creative Wisdom employs diversified means to attain a common end, the nutrition of the animal.

Echinus edulis.

The mouth of this animal is under its body, a situation far from favourable, according to appearance, for the mastication or bruising of its food : if its jaws moved vertically, like ours or the mandibles of a bird ; or if they moved horizontally like those of insects, it would have been attended with no small trouble to an animal whose mouth was underneath, but its five pyramidal jaws with the points of the teeth in the centre, admit an action more accordant with the situation of the mouth. By means of its numerous muscles it can impart a variety of action to the mass and individual pieces that form its oral apparatus, so as to accommodate it to circumstances, a power not possessed by the higher animals. In those Echinidans, whose mouth is in the margin of the anterior part of the shell, no such powerful apparatus is observable, its situation being in front of the animal, it is not as it were under restraint, it has less occasion for the aid either of tentacles in its vicinity, or of a powerful apparatus of masticating organs.

By furnishing these animals with a set of peculiar organs to act the part of hands as well as feet, we have another instance of the care of Divine Providence to adapt every creature to the situation and circumstances in which it is placed. The legs and arms of the higher ani

Ananchites, Spatangus, &c.

mals would be rather an incumbrance to an Echinidan, as well as a deformity; it is therefore furnished with a set of organs better adapted to its peculiar station, wants, and functions, in a numerous set of retractile tubes' capable of the necessary extension, fitted at their extremity with a cup acting as a cupping-glass or sucker, and enabling the animal to adhere, with irresistible force, to any substance to which it applies them, and discharging at the same time the functions of hands to lay hold of their prey

and convey it to their mouth, of legs and feet to stay themselves upon, and of lungs to assist in their respiration.

The workmanship also in these animal structures is as beautiful and striking as the contrivance manifested in them is wonderful. Their protuberances, especially in the mammillary sea-urchin, their variously sculptured spines, their tentacular suckers, all by their perfect finish and admirable forms declare- The hand that made us is divine-since they exceed in all these respects the most elaborate human works.

The third and last section of the Echinoderms, or spiny-skinned Radiaries, are the Fistulidans. Amongst these we may notice the Sea-anemonies, marine animals, fixing themselves to the rocks, but having the power of locomotion, which from a common base send forth what appear to be a 1 PLATE III. Fig. 5.

Fistulides, Lam. 3 Actinia.



number of stalks terminating each in what seems a many-petaled flower of various hues, so that those who have an opportunity of observing them from a diving bell, may see the submerged rocks covered with beautiful blossoms of various colours, and vying with the parterres of the gayest gardens. Ellis, who was the first

, Englishman who opened his eyes to the beauties and singularities that adorn the garden which God has planted in the bosom of the ocean, has named many of these from flowers they seem to represent, as the daisy, the cereus, the pink, the aster, the sunflower, &c.

These animals, at first, appear to come very near the polypes, especially the fresh-water ones, bearing a number of individuals, springing, as it were, from the same root, each sending forth from its mouth a number of tentacles, which are stated to terminate in a sucker, and by which also, like the other Echinoderms, they respire and reject the water; they also reproduce their tentacles when cut off. Portions of the base when divided are reproductive, but they do not separate from the parent till their tentacles are completely formed. Their internal organization, however, is much more advanced than that of the polypes. They have a separate alimentary sac or tube, surrounded by longitudinal muscles,

[blocks in formation]

and even nervous nodules or ganglions, and also several ovaries.

In mild calm weather, when the sun shines, they may be seen in places, where the water is not very deep, expanding their many-coloured flowers at the surface of the waters- but

upon the slightest indication of danger, the flowers suddenly disappear, the animal contracts itself and wears the aspect of a mass of flesh. They as it were, vomit up their young, or the germes formed in the ovaries: but they sometimes force their way out from other parts. When inclined to change their station they glide upon their base, or completely detaching themselves, commit themselves to the guidance of the waves. Reaumur observed them use their tentacles like the Cephalopods, for locomotion. They fix themselves with so much force, that they cannot be detached without crushing them.

It is not wonderful that so many of the lower aquatic animals should have been mistaken for plants, when they so exactly represent their forms, their roots, their branches and twigs, their leaves and their flowers--but besides the irritability of the animal substance, which however is partially exhibited by some plants; there is another character which seems, as a strong line of demarcation, to be drawn between them, and to which I have before adverted ;'

See above, p. 139.


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