The bones help to move our hands and arms, and assist us in walking.
~13.

The Joints.~--The places where two or more bones are fastened together are called _joints_.

Some joints we can move very freely, as those of the shoulder and the hip.

Others have no motion at all, as those of the bones of the skull.
~14.

Cartilage.~--The ends of bones which come together to form a joint are covered with a smooth, tough substance, which protects the bone from wear.