has its junction with the brain: two others, called parietal, form the arch of the head to its centre. To these are joined the frontal bone, or forehead. The ethmoid, a spongy bone, forms part of the orbits, and the hinder part of the nose. The temporal bones contain the organs of hearing, with links connecting them with the cheek bones and the tongue. The sphenoid, a bat-shaped bone, surmounts and combines the whole. The bones overlap and combine with a resistless tenacity. Their saw-like edge gives them great power of adhesion.

Our British forefathers in their rude and primitive condition constructed a huge figure of a man made of wicker-work, which was filled with devotees, and the whole were offered as a sacrifice to their divinities. The peculiar net-work construction of the bones forming the human chest seems to have suggested to their minds the form of the monster alluded to.

The chest is composed of bone and cartilage, and in shape is nearly an elongated oval, and, like an egg, narrower at one end. The bones of the back are known as the dorsal vertebræ; the breast-bone is called the sternum; and the ribs connect the hinder

and front bones together. The breast-bone in its origin consists of five portions; but after the growth

of some years the four lower bones unite together, and form a kind of shield, the edges of which are specially adapted to unite with the ribs.

The ribs are twenty-four in number,-the larger ones being placed in the centre, and the smallest at the extremities: twelve on each side of the frame. The two lower ones do not unite with the sternum.

The pelvis is placed at the extremity of the spine; and consists of four bones, the names of which are the sacrum, the coccyx, and two called innominate. The sacrum is a wedge-shaped bone attached to the spine. In youth it consists of five parts, but these unite in mature age. Attached to the sacrum is the coccyx, -four small bones united, which occupy the place at the extremity of the vertebræ in man, and which forms the tail in lower animals. The two haunchbones are attached to the sacrum, and are known as the innominate. These bones are thick, flat, and strong, and occupy an important place in the body. The head of the thigh-bones are received in a cavity formed in the haunch-bones.

But little observation will be required to discover how important are the duties required to be performed by the chest. The heart and lungs have to be protected from injury; hence we find them enshrined in a citadel, and shielded by strength. Where the organs of respiration are found, there we have defence combined with elasticity, so that their action of expansion and contraction may work freely, yet safely.

The pelvis presents a form remarkable for its strength. The weight of the trunk is constantly

pressing upon it for support; hence we find it is adapted to receive that burden without oppression, and to bear the load with equanimity and comfort. The student who has the opportunity to examine these separate groups of bones, and to learn their fitness for the office each has to perform, will be delighted with the wisdom and intelligence displayed in every part. This is a study commended to all

young persons.

CHAPTER III.

The Upper and Lower Extremities.

ARMS and legs are the common names given to the extremities of the human body. They consist of two pairs of bones. Each of the upper extremities consists of four separate parts, known as the shoulder, the arm, the fore-arm, and the hand.

The first consists of the shoulder-blade and the collar-bone. The shoulder-blade extends from the first to the seventh ribs, and is connected with the trunk by strong muscles, which enable it to move freely. There is a hollow in the upper part of this bone into which the arm is inserted. Numerous powerful muscles and ligaments connect these together, and retain the head of the arm in its place.

The clavicle, or collar - bone, is twisted in shape, small in circumference, but strong, and unites the scapula with the sternum. Its uses are to keep the shoulder in its proper place, and to protect the nerves and other fleshy parts which connect the