We can not all go to the sea to study its wonders. So we will have to do the best we can studying pictures of shells, making collections of as many kinds as possible and studying about the animals that have lived in them. Each shell, it matters not how small, has been the home of a living creature. Each has an interesting story for us if we will but read it. Shell-fish have no bones as other fish have. They, therefore, need a solid house in which to live. The shells not only serve them for houses, but for bones to keep their pliable bodies in shape, for ships in which to sail, and for beautiful dresses, starched and shining. If these soft animals had no solid shells they would immediately be eaten by other animals of the sea or dashed to death by the waves. But it is not alone the beauty of shells that renders them interesting. Conchology, which treats of shells, is as a science at least as old as the days of Aristotle, the study of which was resumed, along with that of the other sciences, when the dark ages had passed away. Since the beginning of the nineteenth century it has given place to a more extended and comprehensive study of molluscous animals, the presence or absence of a shell having been found not to constitute one of the most important characteristics which distinguish different classes of mollusks. Conchology was only the form of the science suited to a time when the shell was more considered than its inhabitant. Yet it is claimed that the relations between shells and the mollusks which possess them are such that the labors of the merest conchologists have contributed to the real advancement of science, both zoölogical and geological. Shells consist of carbonate of lime secreted by the animal and intermixed with some animal matter. In the species in which it is least developed it appears as a hollow plate, which serves as a protection to the breathing organ and heart. The protuberances and ridges seen on many univalve and bivalve shells appear in the course of their growth by the margin of the mantle, turning out at a considerable angle and thus building up a plate in this position for a certain distance. This growth then ceases, the mantle retracts, or may be regarded as changing itself into the shelly layers, and thus it extends in the original direction, carrying out the shell with it, till it turns again to form a second plate or ridge; and so the process goes on. Many mollusks possess the power of altering and enlarging their shells to adapt them to their growth, which they appear to do as if by an intelligent will.