Page:Hardwicke's Science-Gossip - Volume 1.pdf/138
and the earnest will to be converted into an inexhaustible source of amusement and instruction,—
Picking up gold and silver.
Over all, "the lark at heaven's gate sings," the cuckoo utters its well-known note, the little birds twitter in the boughs, the hawk suspends itself 'mid air, and man alone, of all created things, is apt, in getting or spending, to lay waste his powers, to permit the literal El Dorado to absorb the ideal. Where—
Though holding enough, he is longing for more;
And you'll meet him, despite his text profound,
Along with the crowd on Tom Tidler's ground,
Looking for gold and silver.
THE KEYHOLE LIMPET AND ITS PARASITE.
By J. K. Lord, F.Z.S.
THE Keyhole Limpet, I may briefly state for the benefit of the unlearned in shell-fish, is a gasteropodous mollusc, belonging to the family Fissurellidæ, its generic name, fissurella, being derived from the diminutive of fissura, a slit. In shape and colour the shell closely resembles the ordinary limpet (Patella vulgata), so common on our British coasts; possessing a like power of adhering to the rocks, with a tenacity requiring knife and hammer to overcome,—an obstinate adherence, giving rise to a popular saying, "they stick to you like a limpet to a rock"—its shape conical, the base being occupied by a powerful muscle, which is not confined entirely within the shell. It performs the office of legs by its expansion and contraction, a means by which the creature moves from place to place on the rocks; a system of progression you may see for yourselves if you watch a garden-snail taking a constitutional over a cabbage. This muscle also enables it to fix itself at pleasure, aided by atmospheric pressure 15 lbs. to the square inch. They browse on sea-weed, and are usually found between tide-marks.
At the apex of the shell is a hole, somewhat oval; hence the name of Keyhole. This orifice is for the escape of the outgoing branchial current. There are about 120 species inhabiting all parts of the world, India, China, Australia, and the Pacific at Vancouver Island. When shell-collecting near Esquimalt Harbour (Vancouver Island), I frequently picked up empty fissurellas on the beach, but diligent research at dead low water, in the rock pools, failed to discover the living fish, neither did the dredge ever bring one up, from deep or shallow water. The empty house, in this instance, was less desirable than even a bad tenant, as the mansion without its liege lord was a useless ruin.
The tide at Vancouver Island plays all sorts of eccentric freaks, setting all tidal laws at defiance. In May, June, and July, there is but one high and one low water in twenty-four hours; high water at the change and full of the moon happening about midnight. Springs range from 8 to 10 feet; neaps from 4 to 5. In winter there is a complete reversal of this process; but it will suffice for present purposes to state that in summer the water is low during the day, and in winter low during the night.
Macauley's Point, a long ridge of slaty rocks running far out to sea, but bare at low water, was a favourite hunting-ground of mine, the snug little rock basins generally affording some novelty, left prisoner by the receding water. An unusually low tide disclosed a ridge of rocks I had never before seen—an opportunity for exploration not to be neglected. Clinging to the slippery wrack, and scrambling down a vertical ledge, I discovered a regular cave, its sides and floor literally covered with the strangest collection of marine wonders I had ever gazed on:—
E'en yet it was a place of paradise.
****
Here, too, were living flowers,
Which, like a bud compacted,
Now, in open blossom spread,
Stretched, like green anthers, many a seeking head.
Others, like the broad banana growing,
Raised their long wrinkled leaves of purple hue,
Like streamers wide outflowing.—Kehama.
Actinia spread their treacherous petal-like arms, gorgeous in every variety of exquisite colouring; huge Holuthuria, like brilliantly-painted cucumbers, clung to the dripping rock; star-fish of all sizes and tints—chitons in black spiny mail—shells of purpura and trochus, and hosts of kindred Annelides too were peeping from out their cases of stone and horn, their exquisite feathery tufts, fishing-lines, and traps wondrously beautiful, but, like the embrace of a siren, fatal in its clasp;—all these, hungry and anxious, waited for the coming tide. Biding his time like the rest in this stronghold was Sir Keyhole Limpet.