“He quits his cell, the pilgrim staff he bore, And fixed the scallop in his hat before.”[10]
Some mystic connexion, some secret sympathy, was assumed to exist between the scallop and St. James, the brother of the Lord, first bishop of Jerusalem. What it was appears to be irrecoverably lost in the darkness of those very dark ages, and is doubtless not worth the hunting up. We may leave such puerilities, to consider the impress of His divine hand which the All-wise God has made on the shell of the mollusk that inhabits it.
These bivalves have been called the “butterflies of the sea,” as well on account of the vivid and varied colours with which their broad wing-like valves are painted, as of their agile fluttering and flying movements. We frequently see them, especially for some time after having been taken and put into an unfamiliar scene, as our aquariums, shoot hither and thither through the water, with irregular zigzag flights, accompanied with fitful openings and closings of the valves. These leaps and flights seem to have no determinate object, except “the letting off the steam” of their exuberant animal vivacity; but the creatures have the power of directing their leap by a forcible ejection of water from any given part of the compressed lips of the mantle.[11]
It is a very pretty sight to see a healthy Pecten in a vessel of clear sea-water. The elegant valves are opened to a considerable width, perhaps to half an inch or more, and the entire aperture all round is filled by a curtain, which drops from one to the other, perpendicularly, a little way within the margin. This is the mantle, and it is generally painted with rich colours, in irregular patterns, often of spots and marbled clouds of black on a rich green ground, or pearly-green clouds on flesh-colour--sometimes pale-yellow clouds on velvet-black; but these hues have no perceptible relation with those of the shell. Looking closely, you see that the mantle is not single, but composed of two curtains, whose edges meet in the middle. And now these are slightly separating, and giving us a peep into the interior; but the most notable thing we see is the array of long white taper tentacles which proceed from each edge, and wave to and fro in the clear water; while another row of similar organs, but larger, is affixed to each curtain along the line where it starts from the shell. And along this same line, scattered between the bases of the larger tentacles, there is a row (and a corresponding one on the other curtain) of beads, which seem to be turned out of the richest and most lustrous gems. Even the unassisted eye is arrested by the flashing brilliance, but with a powerful lens they look like rubies set in sockets of sapphire, from which the light blazes forth with incomparable brilliance. These are the Pecten’s eyes, each of which possesses all the parts requisite for perfect vision.