And a third form is found consisting of thin pieces, thinner than writing paper, placed on edge, spreading out from a centre, or from a line down the middle of a long strip, and the openings are then plain deep furrows, running from the middle to the outside.
There is also the precious red Coral of which beads and other trinkets are made, found principally in the Mediterranean Sea, and several other sorts, more or less rare. But what I have described to you are the commonest.
This curious substance extends over hundreds of miles in various parts of the Tropical Seas, in islands of different forms. But before I describe these to you, I must tell you what is known respecting the little animals by which it is manufactured, for it is proved to be the work of certain kinds of the little creatures called Polypes.
THE CORAL-MAKING POLYPES.
The Polypes are a kind of animals apparently of very simple structure, without bones, or shells, or heads, or brains. They have very large mouths surrounded by a great number of tentacula, or feelers, which are threads of flesh possessing the sense of touch in great perfection; and to these tentacula they owe the name Polypes, which comes from two Greek words signifying many feet. The ancient naturalists who named them, I suppose did not know but that they were feet.
