“Sullen and sad, with all his rising train;
Vapours and clouds and storms.”
It requires some zeal in the pursuit of scientific lore to leave the glowing fire and the pleasant book, the luxurious arm-chair and the elastic carpet, and to venture down to the wild sea-beach, to poke and peer among the desolate rocks. Yet even now we may find a few bright days, when Nature abroad looks inviting, and when an hour’s marine research will prove neither unpleasant nor unsuccessful.
SQUIRTERS.
On such a noon, then, calm and quiet, the sun bright and cheerful, if low and feeble, the tide tolerably low and the rocks accessible, we hie down to some one or other of those ledges which have so often already yielded their treasures to our search, and begin our wonted labours at turning over the heavy angular masses. We soon find, attached to the under surfaces of these, what seem to be irregular blobs of coloured jelly of somewhat firm consistence, as if an invalid had been here eating his calves’-foot jelly, whose trembling hand had dropped sundry spoonfuls on the stones. Some appear as flattish shapeless drops, but others take more elevated forms, like sacks set on end, and usually displaying two mouths. One of these is of a pellucid yellowish green, or olive hue, with a cloudy spot of rich orange in the interior. A slight shrinking from the touch, a yet closer contraction of the projecting points, is the only token of life that we can discern in it now; but if we place it in an aquarium,—not forcibly removing it from its attachment, but lifting the shell or stone on which it rests; or, if this be too large, detaching the fragment with a chisel,—and allow it to remain a few hours undisturbed, we shall see evidences of a vitality, indubitable if not very active.
The whole creature is now much plumper and more pellucid; it stands up boldly from its base on the stone; its upper portion is much lengthened, and the two wart-like eminences have become two short tubes with gaping extremities, appearing as if they had been soldered together side by side, of which the one is considerably higher than the other.[149]
We have before us one of the Tunicata, an order of molluscous animals which are closely allied to the Conchifera or bivalves, but somewhat lower in the scale than they. It has no shell; that is to say, lime is not deposited in the outer investment, so as to give it the hard, rigid, solid texture of shell; but the internal organs, which are essentially similar to those of an Oyster or a Sand-gaper, are enclosed in a tough leathery coat, known as the test, which is in fact a closed shell destitute of lime. The eminent physiologist, John Hunter, who had dissected some of these homely Squirters, as they are familiarly called, recognised, with his wonted acumen, the structural similarity of their leathery envelopes to the stony shells of the lower bivalves; and, associating them in a group, called them “soft-shells.” The naturalness of this group, since called Tunicata by Lamarck, has been recognised by modern zoologists.
Plate 34.
P. H. GOSSE, del. LEIGHTON, BROS.
ORANGE-SPOTTED SQUIRTER. FOUR-ANGLED SQUIRTER. CURRANT SQUIRTER.