Page:Popular Science Monthly Volume 8.djvu/30

20 first failure. These soundings and grapplings brought from the sea-depths unmistakable proof that life in many varied and exquisite forms existed there, far away from light and vegetation, under an enormous pressure of superincumbent waters; and logic retired discomfited.

The fact that the Ægean Sea is empty of life in its greatest depths is due to local causes. The humblest life, in the farthest recesses of the ocean's bed, is, in some of its essential features, but a sluggish copy of the higher types on land. Food and air are alike necessary



to both. The circulation of currents throughout the open seas bears nutriment and oxygen to the lowly forms of animal life which lie far below the level penetrated by light, or capable of supporting vegetation. In the Mediterranean such currents are obstructed by the high rocky wall which runs under the straits of Gibraltar, from Spain to Africa. The lowest point in this wall is 10,000 feet above some portions of the bed of the Mediterranean. The currents in this sea are therefore superficial, as well as the life sustained by them.

Chemical analysis proves that the water of the open seas contains