The pint of watery fluid from the pancreas and the quart of greenish yellow fluid called _bile_ given out by the liver are carried through two tubes into the intestine (Fig. 27). To mix these juices with the food the intestine is being swung gently back and forth and the walls squeezed together by muscles forming its outer coat. As soon as the intestine has finished its work the food begins to enter the blood. [Illustration: FIG. 27.--The organs which get the food ready to enter the blood.] [Illustration: FIG. 28.--Showing how the food in the dog is carried from the intestine to the liver and heart. The white tubes carry the fats up to the vein in the neck, and the dark tubes which are veins carry the other part of the food to the liver.] =How Food gets into the Blood.=--An hour or two after food has entered the intestine it is almost as thin a fluid as milk. Millions of tiny fingerlike growths stick out from the inner side of the intestines and drink in the watery food. These little fingers for drinking up the food are scarcely one fourth as large as the point of a pencil. They are called _villi_. The villi are filled with blood tubes having thin walls. The food passes through these walls into the blood stream. Much of it then goes to the liver, but the fatty parts flow up a tube along the backbone and empty into a blood tube in the neck. From the neck and the liver the food goes with the blood to the heart which sends it to all parts of the body. =What the Liver does.=--The liver is a dark red body nearly as large as the upper half of your head. It lies just below the diaphragm. It works night and day helping to keep the inner parts of the body clean and at the same time deal out food. The liver takes some waste out of the blood and sends it out into the intestine with the bile. When there is no food in the intestine, the bile is stored up in the _gall bladder_ under the liver. The liver changes certain waste matter in the blood into such form that other organs can cast it out of the body. It also stores up certain parts of the food coming from the intestines and gives it out to the body little by little as it is needed. =When and How much to Eat.=--When the food organs do not do their work rightly, the whole body becomes sick. Eating too much overworks the stomach. It becomes so full that the food cannot be moved about and well mixed with the juices. Germs then work on the food and make it sour. In fact the germs may change part of the food into a poison. This poison will cause headache and a bad feeling. Do not form a habit of taking powders to cure headache. They are likely to hurt the heart. Take less food, eat it more slowly, and do not wash it down with drink. Stop eating before your stomach feels full.