At each end of the stomach is a narrow opening so arranged that it can be opened or tightly closed, as may be necessary.

The upper opening allows the food to pass into the stomach, the lower one allows it to pass out into the intestines.

This opening is called the _pylorus_ (py-lo'-rus), or gate-keeper, because it closes so as to keep the food in the stomach until it is ready to pass out.
~11.~ In the membrane which lines the stomach there are many little pocket-like glands, in which a fluid called the _gastric juice_ is formed.

This fluid is one of the most important of all the fluids formed in the digestive canal.
[Illustration: GASTRIC GLAND.] ~12.

The Intestine~( in-tes'-tine) .-- At the lower end of the stomach the digestive canal becomes narrow again.