_d._ The legs. { Lower-leg bones.
{ Ankle, including heel-bone.
{ Foot and toes.

4. The bones are useful for support, protection, and motion.

5. The place where two bones join is called a joint.

6. The tough substance which covers the ends of many bones is called
cartilage or gristle.

7. The joints are enabled to work easily by the aid of a fluid secreted
for that purpose.

8. The ends of the bones are held together in a joint by means of
ligaments.

9. Bones are about two thirds earthy matter and one third animal matter.

10. The use of alcohol and tobacco may prevent proper development of the
bones.




CHAPTER XIX.

HOW TO KEEP THE BONES HEALTHY.