CHAPTER IV.
THE BONES.
64. The bones are firm and hard, and of a dull white color. In all the higher orders of animals, among which is man, they are in the interior of the body, while in lobsters, crabs, &c., they are on the outside, forming a case which protects the more delicate parts from injury.
65. In the mechanism of man, the variety of movements he is called to perform requires a correspondent variety of component parts, and the different bones of the system are so admirably adapted to each other, that they admit of numerous and varied motions.
66. When the bones composing the skeleton are united by natural ligaments, they form what is called a natural skeleton, when united by wires, what is termed an artificial skeleton.
67. The elevations, or protuberances, of the bones are called proc´es-ses, and are, generally, the points of attachment for the muscles and ligaments.
ANATOMY OF THE BONES.
68. The BONES are composed of both animal and earthy matter. The earthy portion of the bones gives them solidity and strength, while the animal part endows them with vitality.
64. What is said of the bones? 65. Is there an adaptation of the bones of the system to the offices they are required to perform? 66. What is a natural skeleton? What an artificial? 67. What part of the bones are called processes? 68–73. Give the structure of the bones. 68. Of what are the bones composed? What are the different uses of the component parts of the bones?