Now it had often been suggested by Geologists that this wide-spread formation derived its existence chiefly from the accumulated remains of organic life. For in many instances the broken shells of minute animalcules could be distinctly observed to constitute a part of the rock. And even where the organic structure could not be so clearly traced, the carbonate of lime composing the Chalk presented just that appearance which would naturally result from the decomposition of such shells. This theory, however, was long put forward with diffidence and received with incredulity. Even scientific men found it hard to persuade themselves that a solid rock of such great extent and thickness could have been the work of agents apparently so insignificant. But it has been confirmed and illustrated in a very interesting and unexpected manner within the last few years. When the project of connecting Europe and America by a telegraph cable was first set on foot, it became necessary to ascertain, as far as possible, the general configuration of the ocean bottom and the exact nature of the bed on which the cable was to lie. Accordingly in the year 1857 an expedition was fitted out for this purpose under the command of Captain Dayman; and a careful series of soundings was taken between Valentia, on the West Coast of Kerry, and Trinity Bay on the shores of Newfoundland. It was found that the floor of the ocean between Ireland and America is a vast irregular plain, and that by far the greater part is covered over with a kind of soft mud or ooze. Samples of this ooze were scooped up, even at the most profound depths, by means of an ingenious apparatus attached to the sounding-lines, and brought undisturbed to the surface. Afterward they were carried home to England and submitted for examination to Professor Huxley. The result has been to show that the materials of a limestone rock, resembling in every essential feature the White Chalk of Europe, are being spread out at the present day over an area of immense extent on the floor of the Atlantic Ocean.