13.  The Liver.—­Close up under the ribs, on the right side of the body, is a large chocolate-colored organ, called the liver.  The liver is about half as large as the head, and is shaped so as to fit snugly into its corner of the abdomen.  The chief business of the liver is to make a fluid called bile, which is very necessary for the digestion of our food.

14. The bile is a bitter fluid of a golden-brown color.  It is carried to the intestine by means of a little tube or duct, which enters the small intestine a few inches below the stomach.  When the bile is made faster than it is needed for immediate use, it is stored up in a little pear-shaped sac called the gall-bladder, which hangs from the under side of the liver.

15. The liver is a very wonderful organ, and does many useful things besides making bile.  It aids in various ways in digesting the food, and helps to keep the blood pure by removing from it harmful substances which are formed within the body.

16.  The Pancreas(pan’-cre-as).—­The pancreas is another large and very important gland which is found close to the stomach, lying just behind it in the abdominal cavity.  The pancreas forms a fluid called the pancreatic juice, which enters the small intestine at nearly the same place as the bile.

17.  The Spleen.—­Close to the pancreas, at the left side of the body, is a dark, roundish organ about the size of the fist, called the spleen.  It is not known that the spleen has much to do in the work of digestion, but it is so closely connected with the digestive organs that we need to know about it.

18. Please note that there are five important organs of digestion.  The mouth, the stomach, the intestines, the pancreas, and the liver.

19. Also observe that there are five digestive fluids, saliva, gastric juice, bile, pancreatic juice, and intestinal juice.

SUMMARY.

1.  The process of dissolving and changing the food so that it may be absorbed and may nourish the body is digestion.

2.  The work of digestion is chiefly done in the digestive tube or canal, which is about thirty feet in length.

3.  The mouth contains the teeth, and has three pairs of salivary glands connected with it, which make saliva.

4.  The gullet leads from the mouth to the stomach.

5.  The stomach is pear-shaped, and holds about three pints.

6.  It has an upper and a lower opening, each of which is guarded by a muscle, which keeps its contents from escaping.

7.  The lower opening of the stomach is called the pylorus.

8.  The stomach forms the gastric juice.

9.  The intestines are about twenty-five feet long.  They form the intestinal juice.

10.  The liver lies under the ribs of the right side.  It is about half as large as the head.  It makes bile.