One of these in particular has acquired a certain celebrity on account of its size and the peculiar use to which it has been put. It is the gigantic Tridacna, commonly known as the "font," because it is sometimes employed in churches to contain the sacred water. The great Tridacnæ, which are only detached from the rocks by cutting their cable with an axe, sometimes weigh more than five hundred pounds. The natives of the Molucca Islands eat them like we do oysters, to which they are analogous, and the flesh of one is a sufficient meal for twenty people. Their thick valves, which are sometimes five feet long, serve as troughs for the inhabitants, which nature offers ready cut and polished, and which they often use for feeding pigs, or convert into bath-tubs for their children. Buffon speaks of a shell, the diameter of which was equal to that of a carriage-wheel, and which was used for a mill-stone.
Changing Colors in a Dying Mullet.
The mullet is a fish that was much esteemed by the ancients. The Italians have a proverb which says: "He who catches a mullet is a fool if he eats it and does not sell it"—owing to the high price which the fish commanded. When it is dying, it changes its colors in a very singular manner until it is lifeless. This spectacle was so gratifying to the Romans that they used to show the fish dying in a glass vessel to their guests before dinner.
An Immense Zoological Cabinet.
Schleiden maintains that a single visiting card, when it is covered with a white layer of chalk, represents a zoological cabinet containing nearly 100,000 shells of animals. These shells are formed of carbonate of lime, and are so extremely small that it has been calculated that it would require 10,000,000 of them to make a pound of chalk.
Chank-Shell.
This name is given to a shell of several species of Turbinella, a genus of mollusks found in the East Indian seas. They are much used as ornaments by Hindoo women, the arms and legs being encircled with them. Many of them are buried with opulent persons. A chank-shell opening to the right is rare, and highly prized in Calcutta, one hundred pounds being sometimes paid for one.
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.