A Year at the Shore

by Philip Henry Gosse

But all this time our fair “cokill” has been lying at our feet, snapping, and gaping, and thrusting forth and back his great coral foot, waiting our leisure to take him up. No longer shall he be neglected. The bivalve shell is a fine solid house of stone, massive, strong, and heavy, elegantly fluted with prominent ribs that radiate regularly on both valves from the curved beaks, which ribs are beset with polished spiny points. The hues of the shell are attractive, though not at all showy; they consist of tints of yellowish and reddish browns, rich and warm, arranged in concentric bands, and gradually fading to a creamy white at the beaks. Unlike the scallops, the cockles have the two valves alike in shape, and from the bent beaks meeting each other, and the curvature of the outline, they present, when viewed endwise, a very regular and beautiful heart-shape, whence the scientific name of the genus is derived, Cardium, from καρδία, the heart.

The animal which inhabits this strong fortress is handsomer than bivalves usually are. The leaves of the mantle are thick and convex, corresponding to the shell-valves; the edges are strongly fringed in the neighbourhood of the siphons, which are short tubes of considerable diameter, soldered, as it were, together. The mantle has a soft spongy character towards its edges, but towards the back, where it lines the valves, it is very thin and almost membranous. The hue of the former parts is very rich, a fine brilliant orange, with the shaggy fringe of tentacles paler; the siphons are also orange, with the inner surface of the tubes white, having a pearly gleam.

FOOT OF THE COCKLE.

But what was that scarlet knob that we saw protruded and retracted but now? Ha! as it lies, slightly gaping, the lips of the mantle recede, and we catch a peep within of the gorgeous colour. Suddenly the valves open to their full extent, like the folding doors of a drawing-room, allowing exit to a richly dressed lady. Here comes the vermilion tenant! Place for my lady! But what is she? And what is she about to do in her gorgeous raiment? Nay; ’tis but the cockle’s foot; a monopod he is: this is all the foot he has. It is clad in neither shoe nor stocking; and truly it needs it not. Never was the silken-hosed foot of cardinal arrayed like this. But see to what an extent the organ protrudes! four inches from the valves’ edges does its tip reach; smooth, lubricous, taper, with a knee at the upper part, and the toe bent in the form of a hook. As to its general appearance when thus extended, I have compared it to a finger of polished carnelian; but Mr. Kingsley thinks that this resemblance will not hold, the foot being too opaque for that gem: he likens it to a long capsicum, which is, however, too dull and too dark; and he tells a story of a certain (mythic, I fear) countess who, seeing it for the first time, exclaimed, “Oh, dear! I always heard that my pretty red coral came out of a fish, and here it is, all alive!”

Nay; after all, it is what it is; and those comparisons just help one who has never seen it, to form some conception of its appearance; but by one who has, all will be rejected as inadequate.

And as to what the brilliant organ is going to do, that we see. For the long taper foot being thrust to its utmost, feels about for some resisting surface, that stone, half buried in the sand, for instance; which no sooner does it feel than the hooked point is pressed stiffly against it, the whole foot by muscular contraction is made suddenly rigid, and the entire creature,—mantle, siphons, foot, shell and all—is jerked away in an uncouth manner, “quite permiscous,” as the fisherman hard-by says, to a distance of some foot or more. But the cockle can leap on occasion much more vigorously; one has been seen to throw itself clear over the gunwale of a boat when laid on the bottom-boards.

ITS BURROWING FUNCTION.

Thus we see one use of the hooked tip is to afford a stronger spring; but it has a more direct bearing on the burrowing habits of the animal. Like all the rest of its beautiful tribe, this species is a dweller in the deep sand, into which it can penetrate with considerable power and rapidity. In order to do this, the foot is straightened, and the sharp point is thrust perpendicularly down into the wet sand. The muscular force exerted is sufficient to penetrate the soft sand to the whole length, when the point is suddenly bent sidewise, thus obtaining a strong holdfast. The whole organ is now strongly contracted in length, and the animal and shell are dragged forcibly to the mouth of the burrow, the edges of the valves downward and piercing the sand a little way. The straightened point is then pushed an inch or two farther down; again hooked, and another pull is made. The shell descends a little farther into the yielding sand, and the same interchange of processes goes on till the animal is sufficiently buried. To read this description you would suppose it a most clumsy, and ineffective, and slow business; but indeed this is very far from its character. The elongations and contractions are made with great rapidity; and almost with the quickness of thought the unwieldy cockle, when in full vigour and thoroughly alarmed, disappears into his sandy fortress; so fast, indeed, that you must be very alert to overtake him and prevent his descent, if you have no appliances but your two hands.

Cuvier, in his elaborate and beautiful dissections of the Mollusca, has demonstrated that this important organ is mainly composed of an immense multitude of muscles, circular, longitudinal, and transverse, wonderful in their complexity and arrangement, but most perfectly adapted to impart variety, force, and precision to its movements. In these respects the human tongue perhaps presents the closest parallel to its organization. It is remarkable that at its upper or basal part it is hollow, and encloses some of the viscera of the body.

BANDED VENUS.