It is on the north-western coasts of Scotland, however, that the
greatest abundance of these mollusca occurs, and there they form not
a luxury, but even a necessary of life to the poor semi-barbarous
population. The inhabitants of those rocky regions enjoy an unenviable
notoriety for being habitually dependent on this mean diet. “Where
the river meets the sea at Tongue,” says Macculloch, “there is a
considerable ebb, and the long sand-banks are productive of cockles
in an abundance which is almost unexampled. At that time (a year of
scarcity) they presented every day at low water a singular spectacle,
being crowded with men, women, and children, who were busily employed
in digging for these shell-fish as long as the tide permitted. It was
not unusual also to see thirty or forty horses from the surrounding
country, which had been brought down for the purpose of carrying away
loads of them to distances of many miles. This was a well-known season
of scarcity, and, without this resource, I believe it is not too much
to say, that many individuals must have died for want.”[48]
The isles of Barra and North Uist, in the Hebrides, possess also
enormous resources of the same character. “It is not easy to
calculate,” says Mr. Wilson, “the amount of such beds of shell-fish,
but we may mention that, during a period of great distress which
prevailed a good many years ago, all the families in the island (then
about two hundred in number) resorted, for the sake of this food, to
the great sands at the northern end of Barra. It was computed that,
for a couple of summers at the time alluded to, no less than from one
hundred to two hundred horse-loads were taken at low water every day of
the spring-tides during the months of May, June, July, and August. We
were pleased to hear it observed that the shell-fish are always most
abundant in years of scarcity.”[49]
These Barra beds are of great antiquity. A very old writer, Dean Monro,
thus notices them:--“This ile is full of grate cokills, and alledgit
be the auncient countrymen that the same cokills comes down out of the
foresaid hill throw the said strype in the first smalle forme that
wee have spokyn of, and aftir theyr comying down to the sandes growis
grate cokills allways. Ther is no fayrer and more profytable sandes for
cokills in all the worlde.”
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.