Page:Popular Science Monthly Volume 3.djvu/474

460 shallows. Thus depth in the sea corresponded, in its effect upon distribution, to height on the hind.

The same idea is applied to the explanation of a similar anomaly in the Fauna of the Ægean:

The conception that the inhabitants of local depressions of the sea-bottom might be a remnant of the ancient population of the area, which had held their own in these deep fastnesses against an invading Fauna, as Britons and Gaels have held out in Wales and in Scotland against encroaching Teutons, thus broached by Forbes, received a wider application than Forbes had dreamed of when the sounding machine first brought up specimens of the mud of the deep sea. As I have pointed out elsewhere, it at once became obvious that the calcareous, sticky mud of the Atlantic was made up, in the main, of shells of Globigerina and other Foraminifera, identical with those of which the true chalk is composed, and the identity extended even to the presence of those singular bodies, the coccoliths and, the true nature of which is not yet made out. Here, then, were organisms, as old as the Cretaceous epoch, still alive, and doing their work of rock-making at the bottom of existing seas. What if Globigerina and the coccoliths should not be the only survivors of a world passed away, which are hidden beneath three miles of salt-water? The letter which Dr. Wyville Thomson wrote to Dr. Carpenter in May, 1868, out of which all these expeditions have grown, shows that this query had become a practical problem in Dr. Thomson's mind at that time; and the desirableness of solving the problem is put in the foreground of his reasons for urging the government to undertake the work of exploration: