第14章

See, close by is another shell bed, quite as large, but comely enough to please any eye. What a variety of forms and colours are there, amid the purple and olive wreaths of wrack, and bladder- weed, and tangle (ore- weed, as they call it in the south), and the delicate green ribbons of the Zostera (the only English flowering plant which grows beneath the sea). What are they all? What are the long white razors? What are the delicate green-grey scimitars? What are the tapering brown spires? What the tufts of delicate yellow plants like squirrels' tails, and lobsters' horns, and tamarisks, and fir-trees, and all other finely cut animal and vegetable forms? What are the groups of grey bladders, with something like a little bud at the tip? What are the hundreds of little pink-striped pears? What those tiny babies' heads, covered with grey prickles instead of hair? The great red star-fish, which Ulster children call "the bad man's hands;" and the great whelks, which the youth of Musselburgh know as roaring buckies, these we have seen before; but what, oh what, are the red capsicums? -Yes, what are the red capsicums? and why are they poking, snapping, starting, crawling, tumbling wildly over each other, rattling about the huge mahogany cockles, as big as a child's two fists, out of which they are protruded? Mark them well, for you will perhaps never see them again. They are a Mediterranean species, or rather three species, left behind upon these extreme south-western coasts, probably at thevanishing of that warmer ancient epoch, which clothed the Lizard Point with the Cornish heath, and the Killarney mountains with Spanish saxifrages, and other relics of a flora whose home is now the Iberian peninsula and the sunny cliffs of the Riviera. Rare on every other shore, even in the west, it abounds in Torbay at certain, or rather uncertain, times, to so prodigious an amount, that the dredge, after five minutes' scrape, will sometimes come up choked full of this great cockle only. You will see hundreds of them in every cove for miles this day; a seeming waste of life, which would be awful, in our eyes, were not the Divine Ruler, as His custom is, making this destruction the means of fresh creation, by burying them in the sands, as soon as washed on shore, to fertilize the strata of some future world. It is but a shell-fish truly; but the great Cuvier thought it remarkable enough to devote to its anatomy elaborate descriptions and drawings, which have done more perhaps than any others to illustrate the curious economy of the whole class of bivalve, ordouble-shelled, mollusca. (Plate II. Fig. 3.)That red capsicum is the foot of the animal contained in the cockleshell. By its aid it crawls, leaps, and burrows in the sand, where it lies drinking in the salt water through one of its siphons, and discharging it again through the other. Put the shell into a rock pool, or a basin of water, and you will see the siphons clearly. The valves gape apart some three-quarters of an inch. The semi-pellucid orange "mantle" fills the intermediate space. Through that mantle, at the end from which the foot curves, the siphons protrude; two thick short tubes joined side by side, their lips fringed with pearly cirri, or fringes; and very beautiful they are. The larger is always open, taking in the water, which is at once the animal's food and air, and which, flowing over the delicate inner surface of the mantle, at once oxygenates its blood, and fills its stomach with minute particles of decayed organized matter. The smaller is shut. Wait a minute, and it will open suddenly and discharge a jet of clear water, which has been robbed, I suppose, of its oxygen and its organic matter. But, I suppose, your eyes will be rather attracted by that same scarlet and orange foot, which is being drawn in and thrust out to a length of nearly four inches, striking with its pointagainst any opposing object, and sending the whole shell backwards with a jerk. The point, you see, is sharp and tongue-like; only flattened, not horizontally, like a tongue, but perpendicularly, so as to form, as it was intended, a perfect sand-plough, by which the animal can move at will, either above or below the surface of the sand. (2)But for colour and shape, to what shall we compare it? To polished cornelian, says Mr. Gosse. I say, to one of the great red capsicums which hang drying in every Covent-garden seedsman's window. Yet is either simile better than the guess of a certain lady, who, entering a room wherein a couple of Cardium tuberculatum were waltzing about a plate, exclaimed, "Oh dear! I always heard that my pretty red coral came out of a fish, and here it is all alive!""C. tuberculatum," says Mr. Gosse (who described it from specimens which I sent him in 1854), "is far the finest species. The valves are more globose and of a warmer colour; those that I have seen are even more spinous." Such may have been the case in those I sent: but it has occurred to me now and then to dredge specimens of C. aculeatum, which had escaped that rolling on the sand fatal in old age to its delicate spines, and which equalled in colour, size, and perfectness the noble one figured in poor dear old Dr. Turton's "British Bivalves." Besides, aculeatum is a far thinner and more delicate shell. And a third species,C. echinatum, with curves more graceful and continuous, is to be found now and then with the two former. In it, each point, instead of degenerating into a knot, as in tuberculatum, or developing from delicate flat briar- prickles into long straight thorns, as in aculeatum, is close-set to its fellow, and curved at the point transversely to the shell, the whole being thus horrid with hundreds of strong tenterhooks, making his castle impregnable to the raveners of the deep. For we can hardly doubt that these prickles are meant as weapons of defence, without which so savoury a morsel as the mollusc within (cooked and eaten largely on some parts of our south coast) would be a staple article of food for sea- beasts of prey. And it is noteworthy, first, that the defensive thorns which are permanent on the two thinner species, aculeatum and echinatum, disappear altogether on the thicker one, tuberculatum, as oldage gives him a solid and heavy globose shell; and next, that he too, while young and tender, and liable therefore to be bored through by whelks and such murderous univalves, does actually possess the same briar- prickles, which his thinner cousins keep throughout life. Nevertheless, prickles, in all three species, are, as far as we can see, useless in Torbay, where no wolf-fish (Anarrhichas lupus) or other owner of shell-crushing jaws wanders, terrible to lobster and to cockle. Originally intended, as we suppose, to face the strong- toothed monsters of the Mediterranean, these foreigners have wandered northward to shores where their armour is not now needed; and yet centuries of idleness and security have not been able to persuade them to lay it by. This - if my explanation is the right one - is but one more case among hundreds in which peculiarities, useful doubtless to their original possessors, remain, though now useless, in their descendants. Just so does the tame ram inherit the now superfluous horns of his primeval wild ancestors, though he fights now - if he fights at all - not with his horns, but with his forehead.