Page:Popular Science Monthly Volume 56.djvu/250

236 (4) being killed by sudden changes in the temperature and density of the water. Artificial fertilization and the rearing of the embryos in the laboratory largely eliminate these dangers. We have adopted other methods to insure success. A few of the oysters were removed from the Government plant and deposited two miles farther up the bay, nine miles and a half from the ocean, where it was thought the water was warmer, less salt, and loss variable



than on Oysterville Flat. Some, during the breeding season, were placed on spawning floats and anchored near the shore, where the shallow water is thoroughly warmed by the sun. It was in one of these floats that the oystermen had an opportunity to see the oysters spawn "spontaneous," for the water therein, reaching 70° F., became milk-white with spawn or milt within an hour after the oysters had been taken from the plant. This was really our first proof that the introduced oyster would spawn here. Some were