other living species which are found principally in warm and temperate
latitudes. In the Polar ocean none have been discovered, and in the
hotter climates they are most abundant, being found in large beds or
banks near the coast, and often attached to rocks and even to trees which
grow by the water, so that the accounts of some old travellers who stated
that they saw Oysters growing upon trees, were not so false as many
supposed them.
[Illustration]
[Illustration]
The annexed figure is that of the Cock’s-comb Oyster, _Ostrea
Crista-Galli_, a native of the Indian Seas, and a very remarkable shell,
on account of its crooked or deeply indented form; the specific name
means cock’s-crest. The Chinese Window Oyster, called _Placuna Placenta_,
which we may, if we like, translate into a pleasant or agreeable cake;
the shell, it will be seen, is round like a cake, and its smoothness
and regularity of form render it agreeable to look upon; this species
too comes from the Indian Seas, where it is taken on sandy bottoms. The
American Spiny Oyster, or _Spondylus Americanus_, brings us into another
family, that of the Water Clams, called by naturalists _Spondylidæ_; with
the spines stuck out every way, and no way in particular, it looks like a
head of hair greatly in need of the assistance of one of its _pectinated_
relatives. The specific name of this curious shell explains itself; the
generic name comes from the Latin _Spondylis_—a kind of serpent.
[Illustration]
Passing over the family _Malleidæ_, or Hammer Oysters, we come to the
_Meleagrinidæ_, or Pearl Oysters, of which Fig. 1, Plate VIII, is an
example, this is the _M. Margaritifera_ of naturalists, the mollusk
in whose shells pearls are chiefly found. Here are two long words;
_Meleagris_ is the Latin for a Guinea or Turkey Hen, to the markings of
whose plumage naturalists might have imagined the shells of this genus
bore some resemblance. There was, says the mythology, a celebrated hero
of antiquity named Meleaga, but we can hardly suppose that there is any
association between his name and that of a genus of Oysters, of which
edible we read the ancients were very fond, and they are said to have had
a fancy not only for the mollusk itself, but also for the pearls found
in its shell, which at their luxurious banquets they dissolved in wine,
to make the draughts richer, or at all events more expensive; and this
brings us to the specific name of the Pearl Oyster, _Margaritifera_,
which comes from the Latin _Margarita_—a pearl; the French use this word
slightly altered in the spelling, thus _Marguerite_ for both a daisy, and
A PEARL.
This jewel, so highly valued for its chaste beauty, is but a secretion of
animal matter, resulting from the efforts of some uneasy mollusk, annoyed
by a foreign substance, which has found its way into his habitation, to
make the best of an unavoidable evil by enclosing it in a soft smooth
covering. Let us imitate the Oyster, and when annoyed or afflicted,
by meekness and patience, and christian charity, strive to turn our
vexations and troubles into “pearls of great price,” and “goodly pearls,”
like those mentioned in scripture.
It is on the north-west coast of the Island of Ceylon, in the Indian
Ocean, that the Pearl Oyster most abounds, and there it is that the Pearl
fishery is conducted in the most extensive, systematic, and successful
manner; this fishing commences at the beginning of March, and upwards
of two hundred boats are usually employed in it; in each of these boats
are ten divers, who go down to the Oyster-beds, five at a time, and so
relieve each other; there are besides thirteen other men who manage the
boat, and attend to the divers. Altogether it is computed that from
fifty to sixty thousand persons, in some way engaged in the fishery,
or preparation, or sale of the pearls, assemble at and near the scene
of operations, which must be indeed a busy one. The number of Oysters
taken during the period of the fishing, which is about a month, must be
prodigious. One boat has been known to bring on shore, in the day, as
many as thirty-three thousand; they are placed in heaps, and allowed
to remain until they become putrid, when they undergo a very elaborate
process of washing and separating from the shells, which are carefully
examined and deprived of their pearly treasures. The stench arising from
the decomposed animal matter is described as horrible, and the whole
process filthy and loathsome in the extreme; yet out of the slime and
mud and disgusting effluvia, come every year gems of inestimable value,
calculated to adorn the brow of beauty, and form ornaments the most pure
and delicate that can be imagined. For the exclusive right of fishing
on the banks of Ceylon, for a single season, as much as £120,000 have
been paid to the English government by one person, who sublets boats to
others. Pearls vary greatly in value according to their colour and size;
those which are perfectly white are the most valuable; next to these
are those which have a yellowish tinge; the smallest kind, used for
various ornamental purposes, are called seed pearls, the refuse is made
into a kind of confection called _chimum_, highly relished by Chinese
epicures. A single Oyster will sometimes contain several pearls, which
are generally embedded in the body of the animal, but are sometimes fixed
to the shell; it is recorded of one rich mollusk, that there were found
in his possession no less than one hundred and fifty precious jewels; he
must have been a miser, or perhaps he had taken them in pledge from his
less provident neighbours.
From the earliest time, pearls have been considered as valuable
ornaments; they are mentioned in the book of Job, (see chap. xxviii,
verse 18th.,) and are often alluded to by Greek and Roman writers.
Various attempts have been made to imitate them, and one mode of
producing them, practised, it is said, more than a thousand years ago,
is still carried on in China. In the shells of Pearl Oysters, holes are
bored, into which pieces of iron are introduced; these wounding and
irritating the animal, cause it to deposit coat upon coat of pearly
matter over the wounded part, and so the pearl is formed. Artificial
pearls are made of hollow glass globules or little globes, covered on
the inside with a liquid called pearl-essence, and filled up with white
wax. Historians speak of an ancient traffic in native pearls carried on
by this country; and in modern times, British pearls of considerable
value have been discovered, one not many years since, by a gentleman who
was eating oysters at Winchester, was valued at two hundred guineas.
Generally, however, the pearls of this country are inferior in the two
requisites of colour and size.
Interesting accounts of Pearls and Pearl-fishing, will be found in “the
Penny,” and “Saturday Magazines,” and many other works easy of access.
There our young readers may learn of the perils and dangers to which the
poor divers are exposed from the voracious sharks, which hover about the
fishing grounds, and make a dash at their victim, heedless of the written
charms, with which the priest or shark-charmer has provided him previous
to his descent, and of much more than we can find space here to tell. All
we can now do is to give the portrait, as drawn by Thomas Hood, of a lady
who takes up her abode in all the pearl-producing bivalves, and who is
therefore, perhaps on this account, called
[Illustration: THE MOTHER OF PEARL.]
THE MUSSEL AND THE COCKLE.
It is in the _Dimyaria_ division of the _Conchifera_ that we must
look for these familiar bivalves, the Mussel, or, as it is sometimes
spelled, Muscle, and the Cockle; the former called in scientific language
_Mytilus_, which in Latin means simply a shell-fish, and the latter
_Cardium_, which may have reference to the hinge of this bivalve, or
the heart-shape assumed by several of the species; _cardo_, in Latin,
signifying the hinge of a gate, and _cardesco_, a stone in the shape of a
heart.
It is to the _Mytilidæ_ family that we shall first direct our attention,
and here we find the Common or Edible Mussel, (_M. edule_,) and many
other species, in all of which the shell is more or less elongated,
or lengthened out, and pointed at one end. The members of this family
are abundant on most rocky coasts, where facilities are afforded for
the mollusks to moor themselves to rocks, stones, and other substances
covered at high-water, but left dry by the retreating tide. They are not,
however, confined to shores of this description, but are sometimes found
in vast numbers on low sandy or pebbly flats, which run far out into the
sea; these are called beds of Mussels, and are, like the Oyster grounds,
specially cared for and protected. As a ship by its cable, so commonly
the Mussel, by its bissus or beard, is made fast to its anchorage-ground,
be it pebbly or sandy beach, or jutting rock. Sometimes, however, the
mollusk travels, and this is how it manages to do so; it has a stout
fleshy foot, in shape something like that of a chubby child, and this it
can advance about two inches beyond the edge of the shell, then fixing
the point of it to a piece of rock or any other body, and contracting it,
the shell is drawn onward, and sure, though slow, progress is made in any
desired direction. The _Pinna_, as the marine Mussel is called, has a
foot which is cylindrical in shape, and has at the bottom a round tendon,
almost as long as itself, the use of which appears to be to gather in
and retain the numerous threads with which, when inhabiting the shores
of tempestuous seas, it lashes itself fast to the fixed objects around;
these threads are fastened at various points, and then drawn tight by the
animal, whose instinct teaches it that its brittle shell would soon be
broken in pieces, if suffered to roll hither and thither at the mercy of
the waves.
The Mussel has a very curious method of preparing its cable for this
service; it is not woven, nor spun, nor drawn out of the body, like the
web of the spider, but produced in a liquid form, and cast in a mould
which is formed by a groove in the foot, extending from the root of the
tendon to the upper extremity; the sides of this groove are formed so
as to fold over it and form a canal, into which the glutinous or sticky
secretion is poured; there it remains until it has dried into a solid
thread, when the end of it is carried out by the foot, and applied to the
object to which it is to be attached; the canal is then opened through
its whole length to free the thread, and closing again is ready for
another casting; as if conscious how much depends upon the security of
his lines, the animal tries every one after he has fixed it by swinging
itself round so as to put the threads fully on the stretch; when once
they are all firmly fixed, it seems to have no power of disengaging
itself from them; the liquid matter out of which they are formed, is
so very glutinous, or glue-like, as to attach itself firmly to the
smoothest bodies. The process of producing it is a slow one, as it does
not appear that the _Pinna_ can form more than four or five in the course
of twenty-four hours. When the animal is disturbed in its operations, it
sometimes forms these threads too hastily; they are then more slender
than those produced at leisure, and, of a consequence, weaker. On some
parts of the Mediterranean coast, as in Sicily, gloves and other articles
have been manufactured from the threads of this mollusk; they resemble
very fine silk in appearance.
[Illustration]
The foot of the Cockle, of which we here give a figure, is commonly
employed in scooping out the mud or sand, beneath which it conceals
itself; this useful limb assumes the form of a shovel, hook, or any other
instrument necessary for the purpose; it appears to be a mass of muscular
fibres, and to possess great power. As a boatman in shallow water sends
his vessel along by pushing against the bottom with his boat-hook,
precisely so does _Mr. Cardium_ travel; he doubles up his foot into a
club, and by an energetic use of it as a propeller, makes considerable
headway along the surface of the soft sand beneath the waters. In this
way, too, some members of the genus _solen_ force their way through the
sand; while those called _Tellina_ spring to a considerable distance, by
first folding the foot into a small compass, and then suddenly expanding
it, closing the shell at the same time with a loud snap; so that you see
these sober-looking mollusks are sometimes frolicksome fellows; this is
an enforcement of the lesson, judge not by appearances.
Some of the species, both of the Mussel and Cockle families, have very
beautiful shells. We give a representation of one of each, on Plate VIII.
Fig. 2 is the Magellanic Mytilus, (_M. Magellanicus_,) found chiefly
in the Straits of Magellan; it is generally four or five inches long,
the shells when polished are very brilliant, the deep purple colour
changing into rich violet, as they are held in different lights. In most
cabinets the large fan-like delicate shells of the genus _Pinna_ may be
observed; the largest species is that called _Pinna flabellum_, taken in
the Mediterranean; it sometimes exceeds two feet in length. The first of
these names is a Latin word signifying, besides a shell-fish, the fin of
a fish, or the wing feathers of a bird—hence the term pinion; it refers
to the fin-like or wing-like shape of this shell. _Flabellum_ means a
fan, referring probably to the bissus of the mollusk, which is fine and
glossy, like silk, and very abundant.
Many pretty specimens for figuring might be selected from the _Naidæ_,
a family of Fresh-water Mussels, so called from the Naiades, fabulous
divinities of the streams and rivers. The shells of many of these, which
are of considerable thickness, are lined with the most brilliant nacre,
and in these, as might be expected, pearls are sometimes found. One
species, abundant in some English rivers, called the _Mya Margaritifera_,
or, as some say, _Uno elongates_, has long been celebrated for this
valuable production. It was most likely with pearls from this mollusk
that Julius Cæsar adorned a breast-plate, which he dedicated to Venus,
and hung up in her temple. The rivers Esk and Conway were formerly
celebrated as British pearl-fishing grounds; a Conway pearl was presented
by her chamberlain, Sir Richard Wynn, of Gwyder, to Catharine, Queen
of Charles the Second; and in the royal crown of Britain this jewel is
said still to occupy a place. Sir John Hawkins, the circumnavigator of
the globe, held a patent for the pearl-fishery of the River Irt, in
Cumberland. The rivers of Tyrone and Donegal, in Ireland, have, or had,
their pearl-bearing Mussels; we read of one which weighed thirty-six
carats, (a carat is nearly four grains,) but not being of perfect shape
and colour, it was only valued at forty pounds. We also read of another
purchased by Lady Glenlealy, for £10, and found to be so perfect and
admirable, that £80 was afterwards offered for it, and refused.
These _Naidæ_ have not a bissus like the Marine Mussels, they are
therefore never attached to one object; they use their foot as a
propeller in traversing the muddy floor of the pond or river, and they
have a very funny way of getting along indeed; first, they open the
valves of the shell, put out the foot, and after some little hard work,
manage to set themselves up on edge; they then proceed by a series of
jerks, leaving a deepish furrow in the mud behind them.
We will now go to Fig. 3, the Spined Cytherea, the _Cytherea_ or _Venus
Dione_ of naturalists; the meaning of the term is the mother of Venus,
who was, as you will remember, the goddess of beauty, given to this shell
perhaps because it is entitled to occupy a place at the head of the
_Cytherea_, a genus of the _Cardiidæ_, or Cockle family, of which genus
there are about seventy-eight living species; this, as it is the most
rare, is also, perhaps, the most beautiful; it is found in the seas of
America, and is remarkable for the row of spines on the hinder border of
each valve; these vary much in size and number, being in some individuals
long and far apart, in others, short, thick, and closely set. The colour
of the shell also varies considerably, being sometimes of a delicate
rose colour; at others, more of a claret; at others again, bordering on
purple. It was for one of the first discovered specimens of this shell,
that £1000 is said to have been given. Truly a Venus of value this; it
ought to be called the Queen of Cockles!
Our next example, (see Fig. 4,) is the Spotted Tridacna, (_T.
maculatus_,) the latter term signifying spotted. In the _Chamidæ_ or Clam
family, is placed the _Tridacna_ genus, the discovered species of which
are not numerous; they are chiefly found in the Indian seas. The one
above mentioned claims pre-eminence for beauty. We cannot quite see the
applicability of the generic name; _Tridacnus_, in Latin, signifies to
be eaten at three bites, but he must be a man of large capacity indeed
who could so devour the head of this family, the Giant Tradacna, (_T.
gigas_,) a single specimen of which has been known to weigh as much as
five hundred and seventy pounds; from three to four hundred is by no
means an uncommon size. The shell of this giant mollusk is of a very
picturesque shape, something like its spotted _congener_, as we call
anything of the same kind or genus, only it is somewhat plainer, and more
deeply ribbed and indented. The inside is of a glossy whiteness, and it
is frequently used as a basin for garden fountains, or the reception of
rills or little jets of water, which sparkle in its stainless hollow. In
the church of St. Salpice, at Paris, is a shell of this immense Clam, the
valves of which are used as receptacles for holy water; it was presented
to Francis the First, by the republic of Venice. Fancy the clapping to of
such a pair of valves, when the animal closes its shell in alarm, and the
strength of the cable required to moor it to the rocks or coral reef. The
spotted species here figured has a solid and heavy shell, very elegantly
shaped, and beautifully marked, as will be seen; the greatly reduced size
of the figure prevents anything like justice being done to the original.
[Illustration]
The above is a figure of the Heart Isocardea, (_I. cor_,) which is also
a member of the Clam family, and one of the most elegantly-shaped shells
in the whole range of Conchology. It is a native of the Mediterranean
and other seas of Europe, and has been taken in deep water on the West
coast of Ireland. We complete this group with a representation of the
curious _Arcadæ_ family, or Ark shells, as they are commonly called,
because one of the species was thought to resemble the ark built by Noah.
Mr. Swainson tells us that the animals of these shells affix themselves
to other bodies by a particular muscle, which is protruded through the
gaping part of the valves; they also adhere, when young, by means of
the bissiform epidermis, or bissus-like outer skin: this species is a
native of the Atlantic Ocean and the seas of Europe. The Antique Ark,
(_A. antiqua_,) is very like the Common Cockle, being of a white colour,
and heart-shaped. We give below a representation of this shell, and also
of the shell of the pretty little Pearly Trigonia, (_T. margaritacea_,)
included in the _Arcadæ_ family; this is a rare species, found only in
the seas of New Holland.
[Illustration]
[Illustration]
SCALLOP SHELLS.
Several species of Scallop Shells are found scattered about on our
shores; they belong, as before stated, to the family _Pectinidæ_, the
meaning of which term has been already explained. These shells were
called by Cuvier “the Butterflies of the Ocean,” on account of the
various and beautiful colours which they exhibit. Some of them are
exceedingly thin, and brittle as glass; one species found in the Arctic
regions, is as transparent as that substance, and is therefore called
_P. vitreus_, from the Latin for glass, which is _vitreum_. One of
the commonest of our native Scallops is the St. James’ Cockle, (_P.
Jacobœus_;) this shell is found in great plenty along our southern
coasts; it is often referred to by old writers, on account of having
been commonly worn in the hats of pilgrims to Palestine, or the Holy
Land, as the scene of our Saviour’s life and death was called. Sir Walter
Raleigh, in his poem called “The Pilgrimage,” thus enumerates the
different articles considered necessary for a Palmer, as these pilgrims
were termed:—
“Give me my _scallop shell_ of quiet,
My _staff_ of faith to lean upon,
My _scrip_ of joy, (immortal diet,)
My _bottle_ of salvation,
My _gown_ of glory, hope’s true gage,
And thus I’ll make my pilgrimage.”
This Mollusk, it may be noticed, like many other bivalves, has a flat,
and a concave or hollow shell: in early times when plates and drinking
vessels were not so plentiful as they are now, one of these served the
former purpose, and the other the latter; thus, in speaking of a feast, a
Gaelic or Scottish bard has said—
“The joy of the _shell_ went round.”
Sometimes the species termed _Pecten opercularis_, was used as the
pilgrim’s badge; the specific name comes most likely from the Latin
_operculum_, whose meaning has been explained.
[Illustration: COMMON SCALLOP.]
This too, is a common British shell, as is also the little speckled
Scallop, (_P. varia_,) which may be found on almost any part of the coast
where the water-line is margined with a sandy ridge. The shells are
generally about two inches long, of various colours, clouded, speckled,
and marked with about twelve ribs. There is a foreign species called
the Flounder Scallop, _P. pleuronectes_, which is remarkable for having
the two valves of the shell of different colours, the upper one being
of a rich reddish brown, and the lower one white: the specific name has
reference to this, being compounded of the Latin _pleura_—something
double, and _necto_—to join. The fish called the Flounder, is brown above
and white beneath, hence the English name of this shell. The preceding
engraving of the Common Scallop, viewed from the front, shows the flat
and concave form of the two valves of this shell, and also the depth of
the indentations or ridges.
LIMPITS.
Among the rocks of the British coast, there are no shells more frequently
met with than those of the Common Limpit, _Patella vulgata_; they lie
scattered about like so many little empty cups, each having, on the
death of the mollusk, fallen from the rocky cavity in which it was
embedded, and which was just large enough to contain it. Here the animal
attaches itself so firmly by its fibrous foot, which is hollow in the
centre, and acts like a sucker, that it is almost impossible to loosen
its hold otherwise than by inserting something thin, like the blade
of a knife between it and the stone. By this power of adhesion, the
Limpit is protected from the violence of the waves, and also from its
numerous enemies, aquatic birds and animals, which have a relish for
its flesh. Still vast numbers are used as food, both by man and the
inferior creatures, so that the means of defence furnished to the Limpits
of the rock, are not always sure. “The peasantry of the western isles
of Scotland,” we are told by Miss Pratt, “look to the Periwinkles and
Limpits, which abound on the rocks, for their daily meal, often for long
seasons, subsisting almost entirely upon this humble food. In the Isle
of Skye, the inhabitants are often, at one time of the year, without any
other source of provision.” Then comes the Sea-gull, and the Duck, and
the Pied Oyster-catcher, to feed on the poor little mollusk, the bill of
the latter bird being admirably adapted for loosening its hold on the
rock.