Forest and Stream, October 30, 1879
MORE OYSTER STATISTICS.
Sea -- Shellfish - Oystering : MarketsSea -- Shellfish - Oystering : PackingSea -- Shellfish - Oystering : Yield
THE mathematical man of the Philadelphia Times has been computing the magnitude of the American oyster trade. This is what he makes them: --
Oysters are planted and grown in the bays, deltas, and river inlets of more than three thousand miles of our Atlantic coast. Three thousand acres are so occupied in the Chesapeake bay and its tributaries. These Chesapeake beds yield to our commerce over 25,000,000 bushels annually.
In the one city of Philadelphia, I estimate, there are over four thousand places where oysters are sold for consumption on the premises. One Philadelphia oyster cellar, three years ago, sold 7,000 oysters on the first day of September. Twenty dollars would be a moderate average for the sales of all these 4,000 oyster restaurants, saloons, and cellars. This would bring the total daily sales up to $120,000 a day. Multiply the daily sales by 240 days would swell the yearly aggregate to $30,000,000 a year for oysters in Philadelphia. And yet this estimate is probably considerably below the actual fact.
New York city probably sells twice as many as Philadelphia; and Boston and Baltimore together more than New York again. Aside from the home consumption, the shipments to our inland, Western and even Pacific States are enormous. The appetite of all inland and mountain men for all sorts of shell fish is something huge. Baltimore employs more than $15,000,000 in the canning of oysters. More than 20,000,000 bushels of oysters are canned a year in that city.
On account of their superior excellence American oysters are now exported in vast quantities to England, France Germany, and other European countries. These exportations are mostly in cans, but immense quantities are now shipped abroad in the shell. After to-morrow you will not see an ocean steamer go out of Philadelphia, Baltimore, or New York which does not contain a hundred barrels or more of American oysters still in the shell. The total of our oyster trade approaches much nearer our annual crop of cotton and wheat than any one who does not make these things a special study would be willing at first to credit. I am satisfied in my own mind that our total oyster trade, domestic and foreign, exceeds $300,000,000 a year, while the total annual consumption in this country, and our shipments abroad would exceed the amazing total of 50,000,000,000 oysters.
Prof. Brooks, of John Hopkins University, has been experimenting upon the artificial propagation of oysters. The process of making embryonic bivalves is as follows:
Half a dozen served on the half shell served on a plate, a few watch crystals, a small glass jar, a little water, and the microscope constituted the laboratory. The oysters had been taken fresh from their beds and opened carefully. In this way they will live for a day or two if kept in a cool place, and all the while the heart may be seen to pulsate in its cleft next to the muscles. Close to the heart lay what is usually called the "fat," but which is really the reproductive organs. These are wrapped all around the stomach, liver, and digestive organs, the latter being the "belly" or dark parts of the oyster. The flaps extending around the whole of one side of the shell are its gills, through which it breathes and separates its food. The mouth is at the butt end of the shells, where the hinge connects them. Male and female oysters on the half shell cannot be told apart, and indeed one in fifty is believed to be hermaphrodite. It is claimed that oysters are female when young, and males when they become old and larger. But the facts have not been established with certainty, nor is it of importance. To produce free swimming ciliated embryos, the operator pinched away with tweezers a particle of the generative part, put it into a watch crystal, and stirred it until the eggs were well shaken out. The water was now milky from the great number of eggs. The microscope determined the sex, which in the present experiment proved to be male. Under the microscope these male cells appeared to be dots, perpetually in active motion, and each one of them being sufficient for impregnation when properly lodged. The female eggs are 100,000 larger than the male cells, but are invisible to the naked eye. Having been washed out into separate watch crystals, the eggs are mixed with the male cells. Then viewed under the microscope, the male cells are seen to attach themselves vigorously to the egg in eager crowds, but only one of the many is supposed to impregnate. The first change apparent is the disappearance of the germinal vesicle and this is accomplished in a very few minutes. The egg then becomes spherical and remains quiet for one or two hours, when a kneading process becomes visible. A globule appears on the surface, and this is the beginning of segmentation. Then by degrees the egg becomes divided into smaller and smaller granules. This process of subdivision occupies two hours, and at the end of this time a small, transparent swimming embryo is found, which is the oyster in its infantile state. The whole process occupies from four to six hours, according to the temperature, although in the present instance it was brought to a successful issue in four hours. Professor Brooks, in his previous experiments, had raised oysters till they possessed the cilia, which served to propel the microscopic animal; but they died without further revelation of the mystery of life. In the present experiment he had the satisfaction of developing the embryos until he could clearly trace their digestive organs, and he is inspired with the hope that continued watchfulness will enable him soon to see the infants begin to assume their armor of shells. It is believed that there is no specific time for the spawning season of the oyster, and that it continues throughout the summer months, though this is a point not yet definitely settled.