Edifices of the Polypi.
The prodigious surface over which the combined and ceaseless toil of these little architects extends, must be taken into consideration in order to understand the important part they play in nature. They have built a barrier of reefs 400 miles long round New Caledonia, and another which extends along the northeast coast of Australia 1000 miles in length. This represents a mass in comparison with which the walls of Babylon and the Pyramids of Egypt are as children's toys. And these edifices of the Polypi have been reared in the midst of the ocean waves, and in defiance of tempests which so rapidly annihilate the strongest works constructed by man. They build their reefs and islands with remarkable rapidity. One of the straits in the approaches to Australia, which a few years ago only possessed twenty-six madrepore islands, at present displays one hundred and fifty.