Again, by this allusion to the “tucking in” of Oysters, a phrase more expressive than polite, we have recalled to memory the saying of a quaint old author, that they are “ungodly, uncharitable, and unprofitable meat; ungodly, because they are eaten without grace; uncharitable, because they leave nothing but shells, and unprofitable because they must swim in wine.” Not, generally, however, are they eaten in this luxurious manner, a little pepper and vinegar is all they commonly get in the way of sauce, and those who swallow them thus accompanied, seem to do so with infinite relish. A very long chapter, if not a whole book, might be written about the historical associations of Oysters, for which our country has been famous, as far back as the time of the first Roman invasion; much, too, might be said about the Oyster beds and fisheries, which give employment to thousands of our industrious population, but all this has so little to do with natural history, that we can find no excuse for dwelling upon it here. It is quite within the range of our subject, however, to state that the “spat” or “spawn” of the Oyster is cast about the beginning of May: at first it resembles a drop of greenish tallow, but by the aid of the microscope it may be seen to consist of a great number of minute particles, each of which is an egg, and will by-and-by become a perfect fish; these increase in size very rapidly, and after floating about for a while, sink to the bottom, and become attached to rock or some other substance, in which position, if not violently detached or removed, they complete their growth, and live out the term of their natural life. Their food is minute animalculæ, and microscopic vegetation, on the nature of which their flavour greatly depends.
They have many enemies besides man; the whelk, and the crab, the sea-star, or “five fingers,” and the large drum-fish, which swallows them almost by the bushel, shells and all; these help to thin the Oyster-beds, and make the dredger’s labours less remunerative than they would otherwise be. Here is a picture of one as he stands in his boat just about to throw his dredge into the sandy bottom, where he knows the delicious testaceans do, or ought to, lie most thickly. The dredge, which is a triangular iron frame with a net over the bottom, will naturally sink, and when the line to which it is attached ceases to run out, the dredger will put his boat in motion, and draw it thus over the Oyster-bed, and then pull it up filled, it may be, with little fat “Miltons,” or large “Colchesters,” or such other kind as the spot is known to yield.
The Latin for Oyster is Ostrea, and that is a name given to a genus of the Pectinidæ family, comprising beside the O. edulis, or Common Oyster, many other species. Edulis means eatable. Home naturalists divide these Ostraceans into two groups, first with simple or undulated, but not plaited valves; second, those which have the borders of their valves distinctly plaited.
To the first group belong the Common Oyster, and between thirty and forty 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.
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.
