OYSTER. 



119 



been able to spread over a large part of the world, six 

 of our fourteen acknowledged species being European 



Hawk-OwL 



as well as American. The burrowing owl (Speotyto 

 cunicularia), which ranges from Canada southward to 

 Patagonia, affords another example of the similar 

 wide distribution of a remarkably interesting species. 



OYSTER. The American oyster ( Ostretil'irginica) 

 (, v , -IT VIIT ' las a W '^ e ra "K e f distribution, being 

 . 106 <p 110 found at a " su i taD l e points along the 

 Am Ren ) Atlantic coast from Florida to" the 



southern shores of the Gulf of St. Law- 

 rence, and along the northern coast of the Gulf of 

 Mexico. In some portions of this range it occurs in 

 natural K'lls of enormous extent ; that of Long Island 

 Sound is said to be fully 115 miles in length, the oysters 

 not being confined to the sound but extending around 

 New York Bay and into the small bays along the 

 Jersey shore. Oysters are often brought here from 

 Chesapeake Bay and planted in the sound to supply 

 the beds that have become exhausted by over-dredging. 



In the waters of Virginia there is said to be 2,000,000 

 acres of oyster beds, while in Chesapeake Bay, with 

 its many inlet* and river mouths, the oyster finds its 

 best adapted home, the bivalve here attainingits 

 highest excellence and flourishing enormously. The 

 bottom of the bay is almost covered with beds of the 

 finest oysters in the world. Baltimore is the most im- 

 portant mart in the oyster trade and cans and pickles 

 vast quantities of oysters for shipment to the West and 

 to foreign countries. Farther down the coast oysters 

 occur plentifully but are only gathered for local use. 

 On the coast of Georgia they are said to exist in such 

 multitudes as to form natural breakwaters sufficiently 

 firm to resist the billows of the ocean. The coast 

 region here is made up of salt marshes from twelve to 

 eighteen miles wide, through which slow-flowing rivers 

 make their way to the sea. These streams flow be- 

 tween banks of living oysters, so closely compacted 

 that a vessel might, in some places, obtain a cargo in a 

 space not more than three times its length. 



Oysters abound in the inlets and small bays on the 



north shore of the Gulf of Mexico. In the Bay of 



Mobile they are plentiful and of excellent quality, and 



arc cultivated on a large scale. la Louisiana are beds 



VOL. IV.- u 



of oysters said to be unsurpassed in size and flavor. 

 On the Pacific coast oysters occur abundantly in the 

 Strait of Fuca and in Puget Sound ; these are quite 

 small, but of fine flavor. The Eastern oyster has been 

 introduced and seems to be susceptible of easy cultiva- 

 tion. 



The American oyster is exceedingly prolific, far more 

 so than its European counterpart, which produces about 

 2,000,000 young, while the American bears from 

 10,000,000 to more than 60,000,000 in some instances. 

 The European oyster takes some degree of care of its 

 young, keeping them within the folds of the mantle 

 until they are several days old, while in the American 

 oyster fertilization takes place in the water and the 

 young are exposed from birth to the perils of the 

 waves, so that they are destroyed in far greater 

 numbers than in the case of the European. The 

 minute embryo bivalves swim about by the aid of cilia 

 for several days, feeding on the minutest life-forms of 

 the ocean, after which they fix themselves to some 

 substance to which one of the shell valves becomes 

 cemented. There, if not artificially removed, the re- 

 mainder of their life will be spent. The American 

 oyster grows much faster than the European and 

 attains a considerably greater size. At the end of a 

 fortnight's growth it is of the size of a pin's head ; in 

 three months it attains the size of a pea ; then it 

 grows more _ rapidly, becoming an inch long in six 

 months. It is ready for market in about three years, 

 and its average life is about ten years, though thirty- 

 year-old oysters have been known. These old oysters, 

 at tunes, attain great size ; one found in Mobile Bay 

 is said to have been more than 3 ft. long and nearly 

 2 ft. broad, but they rarely exceed 3 in. in width, 

 though often found over a foot long. When grown 

 under favorable circumstances the shells, at first round, 

 become oval in shape with undulated and scalloped 

 edges, but after the first winter become elongated and 

 irregular, the shape being greatly governed by that of 

 the object to which the oyster is attached. In the 

 natural banks the oysters become so crowded that they 

 are apt to stand in a vertical position, the hinge down- 

 ward and the mouth of the shells upward. Being 

 contracted laterally they often become very long and 

 narrow, forming what are known as "raccoon oysters," 

 or ' ' cat's tongues. ' ' The lower layers of these beds are 

 smothered and die through the annual additions above. 



The mortality of the young oysters is enormous, 

 very few individuals of each batch of millions sur- 

 viving. They have many enemies, while great num- 

 bers perish from lack of a clean surface to which to 

 attach themselves, being smothered in their embryo 

 state by a very thin layer of mud or slime. The 

 mature oysters, also, have many enemies, chief among 

 them the star-fish and the "drill," or boring whelk, 

 yet in spite of these and their human foes, it is only 

 the lack of proper conditions of sea bottom that limits 

 the indefinite increase of the oyster beds. The oyster, 

 in fact, cannot live except under certain conditions of 

 depth and salinity of water, and of firmness of bottom, 

 a mixture of clay and mud forming favorable ground. 

 Soft mud is fatal, and deposits of mud through storms 

 may cause great injury. The young oysters attach 

 themselves to the shells of older ones and beds of 

 great thickness are thus gradually formed. On the 

 western coast of Florida, and in other tropical regions, 

 they attach themselves to the roots and limbs of the 

 mangrove trees. Natural beds can be enlarged and 

 artificial beds made by the deposition of shells, gravel, 

 or tiles over muddy bottoms. Oyster-shells are much 

 used as "cultch," to which the young fry attach 

 themselves and from which they may be transplanted. 

 Seed-oysters are thus carried from Virginia and Mary- 

 land to the beds of the North, where they are planted 

 in shoal waters to be fattened for market. 



Prof. Ryder speaks of having examined oyster 

 beds in water so shallow that the animals are almost 

 entirely exposed to the air during low tide. In severe 



