In 1775 all the oysters in the bay died. What caused their destruction is not certainly known, but it is supposed that as, at this time, a large number of blackfish died and came on shore, where their carcasses remained, producing a very filthy condition of the water, it caused this mortality. A more probable explanation is given by Mr. E. P. Cook of Wellfleet. The early inhabitants, not knowing the value of the natural shell beds for catching the spat, greedily took every shell and burned them into lime as a fertilizer for their farms and plaster for their houses. There was once a fine strip of woods near this original oyster rock, but this was cut down, and the sand gradually washed over the beds, killing the young oysters. To these two causes can be attributed the final destruction of the natural beds in 1775. (2) _The Bedding of Southern Oysters._--After the destruction of the natural beds, an important industry arose in the "bedding" of southern oysters for northern trade. Privileges for bedding oysters on the flats were granted to a number of oyster firms. These men hired schooners in the latter part of the winter or the early spring, which went to the southern oyster grounds and brought back loads of oysters. These oysters were spread or bedded over the leased flats of the harbor, where they remained until the following fall, when they were taken up for market. In this way the oysters gained in size by the summer's growth, and were fattened for market. Considerable trade sprang up in the carrying of oysters, and many vessels were engaged in this traffic. In 1841 Mr. Gould, the conchologist, states that 120 men, with 30 vessels of about 40 tons each, were employed for three months of the year, and brought to the town an annual revenue of $8,000. In 1841 Capt. William Dill is credited with bringing into Wellfleet the first cargo from Virginia, which started a large trade in Chesapeake oysters. Mr. Ernest Ingersoll makes the following statement concerning the Virginia trade:-- Nevertheless, it was not until about 1845 or 1850 that the business began to confine itself to Virginia oysters, and a large business to be done. At its height, about 1850, it is probable that more than 100,000 bushels a year were laid down in the harbor; some say 150,000.... The favorite ground was at the mouth of Herring River. The Rev. Enoch Pratt writes, in 1844:--