_The Absorption of Sugar._—The sugars pass into the blood through the portal circulation, and not through the lymphatic vessels. The question is, Where does sugar go after it gets into the blood? The proportion of sugar in the general circulation is not greater after a meal than before it. It is necessary that there should be some means of storing it, for it cannot all be immediately used for the production of energy. Is it stored as glycogen? Bunge believes that a considerable amount of carbohydrate is stored as fat, since the total amount of glycogen in the liver never exceeds 150 grams, and there is a similar store in the whole mass of muscles. It is evident, therefore, that only a small proportion of carbohydrates is laid down as glycogen, and we must assume that the greater part of it is converted into fat. That fat accumulates in the body on a purely carbohydrate diet is proved beyond a doubt, and the formation of fat from sugar is considered proved by experimental evidence. Sugar is an important source of energy for the muscles, and provision is made for a sufficiency of it always to be in the blood circulating through them, and the storehouse from which it is derived is the liver. When the liver and muscles contain enough glycogen to keep the blood supplied with it, the excess of sugar is converted into fat, and is reconverted into sugar when there is a demand for it. _Mechanics of Digestion in the Intestines._—The intestinal movements, like those of the stomach, have recently been studied by means of the _x_-rays. There are three kinds: A pendulum-like motion, consisting of a gentle, swaying, rhythmic movement occurring in all parts of the intestines. These movements do not affect the whole of the gut at one time, but occur in successive segments of it, and are more obvious in those parts which are distended with food, at a period of three or four hours after a meal. They are most energetic in the upper and least so in the lower part of the gut, and proceed from above downward with the course of the food. The movement consists in lengthening and narrowing, followed by shortening and widening, of the canal; the contraction involves both the longitudinal and circular muscular coats, and in the course of its progress divides the bowel into many segments. This movement breaks up the food, sways it backward and forward, diffuses the digestive fluids through it, and drives chyle into the lacteals. The second kind of movement consists of peristalsis, or wave-like propulsive movements; also localized dilatation, followed by contraction of the canal, progressing from above downward at the rate of 1 or 2 inches per second, and is from three to four hours traveling the entire length of the intestines. Under pathologic conditions a third movement is observed, consisting of a swift venicular movement, starting at the pylorus and traveling the entire length of the gut in about one minute. It is produced by toxins, gases, and other irritants.