First Book in Physiology and Hygiene
3. The bones are covered by the flesh.
4. The bones of the head form the skull, which is hollow and contains the brain.
5. A row of bones arranged in the back, one above another, forms the backbone. The backbone has a canal running through it lengthwise, in which lies the spinal cord.
6. The trunk is hollow, and has two chambers, one called the cavity of the chest, and the other the cavity of the abdomen.
7. The chest contains the two lungs and the heart.
8. The abdomen contains the stomach, liver, and many other very important organs.
~1.~ We all know very well that if we do not eat we shall rapidly lose in weight, and become very weak and feeble. Did you ever think how much