4.  The Skeleton.—­All the bones of an animal, when placed properly together, have nearly the shape of the body, and are called the skeleton (skel’-e-ton).  The skeleton forms the framework of the body, just as the heavy timbers of a house form its framework.  It supports all the parts.

5.  The Skull.—­The bony part of the head is called the skull.  In the skull is a hollow place or chamber.  You know that a rich man often has a strong room or box in his fine house, in which to keep his gold and other valuable things.  The chamber in the skull is the strong-room of the body.  It has strong, tough walls of bone, and contains the brain.  The brain is the most important, and also the most tender and delicate organ in the whole body.  This is why it is so carefully guarded from injury.

6.  The Backbone.—­The framework of the back is called the backbone.  This is not a single bone, but a row of bones arranged one above another.  Each bone has a hole through it, about as large as one of your fingers.  A large branch from the brain, called the spinal cord, runs down through the middle of the backbone, so that the separate bones look as if they were strung on the spinal cord, like beads on a string.

7.  The Trunk.—­The trunk of the body, like the skull, is hollow.  Its walls are formed partly by the backbone and the ribs and partly by flesh.  A fleshy wall divides the hollow of the trunk into two parts, an upper chamber called the chest, and a lower called the abdomen.

8.  The Lungs and Heart.—­The chest contains a pair of organs called the lungs, with which we breathe.  It also contains something which we can feel beating at the left side.  This is the heart.  The heart lies between the two lungs, and a little to the left side.

9.  The Stomach and Liver.—­In the abdomen are some very wonderful organs that do different kinds of work for the body.  Among them are the stomach, the bowels, and the liver.  There are, also, other organs whose names we shall learn when we come to study them.

10.  Care of the Body.—­We have only begun to study the beautiful house in which we live, and yet have we not learned enough to show us how great and wise is the Creator who made us and all the wonderful machinery within our bodies?  If some one should give you a beautiful present, would you treat it carelessly and spoil it, or would you take good care of it and keep it nice as long as possible?  Ought we not to take such care of our bodies as to keep them in that perfect and beautiful condition in which our kind and good Creator gave them to us?

SUMMARY.

1.  The body has a framework, called the skeleton.

2.  The skeleton is made up of many different parts, each of which is called a bone.