_Cellulose_ is the coarse woody fiber found in the stems of all plants and in the outer coating of the various grains. Unless cellulose is very young and tender, it is not digested by the human digestive system. However, some forms of it are of value, as they give bulk to the food residue in the digestive tract, and thus stimulate the activity of the intestinal muscle. In this way, cellulose acts as a natural laxative, and in some cases is a very desirable substance to have in the food eaten. The bran of wheat and other cereals is an especially valuable form to use. _Starch_ is found in all cereals, in many vegetables, in some fruits, and in nuts. It occurs in these different foods in the form of a white, granular substance. The granules have characteristic forms for the different grains, fruits, etc., which can be recognized by the aid of the microscope. Raw starch is insoluble in cold water; hence to be most readily digested, it should be cooked. The cooking process ruptures the granules, and makes the starch itself partially soluble; and in this form, it is more easily attacked by the digestive juices. _Dextrin_ is formed by heating starch to about 350° F., as in an oven. This degree of heat changes the starch chemically to dextrin. In this dextrin form, it is soluble, and is in reality one step along in the process of digestion. TABLE A--CEREALS AND LEGUMES A. Per cent Water B. Per cent Protein C. Per cent Fat D. Per cent Carbohydrate E. Per cent Ash F. Calories per oz. Protein G. Calories per oz. Fat H. Calories per oz. Carbohydrate I. Calories per oz. Total ----------------------------------------------------------------------- FOOD A B C D E F G H I ----------------------------------------------------------------------- Beans, baked 68.9 6.9 2.5 19.6 2.1 8.0 6.6 22.7 37.3 Bread, white 35.3 9.2 1.3 53.1 1.1 10.7 3.4 61.6 75.7 Bread, whole wheat 38.4 9.7 .9 49.7 1.3 11.3 2.4 57.7 71.4 Corn bread 38.9 7.9 4.7 46.3 2.2 9.2 12.4 53.7 75.3 Corn flakes 8.5 9.3 .5 78.7 2.6 10.8 1.3 91.3 103.4 Hominy, cooked 79.3 2.2 .2 17.8 .5 2.6 .5 20.6 23.7 Macaroni, cooked 78.4 3.0 1.5 15.8 1.3 3.5 4.0 18.3 25.8 Oatmeal, boiled 84.5 2.8 .5 11.5 .7 3.2 1.3 13.3 17.8 Peas, green, cooked 73.8 6.7 3.4 14.6 1.5 7.8 9.0 16.9 33.7 Rice, boiled 72.5 2.8 .1 24.4 .2 3.2 .3 28.3 31.8 ----------------------------------------------------------------------- TABLE B--FRUITS A. Per cent Water B. Per cent Protein C. Per cent Fat D. Per cent Carbohydrate E. Per cent Ash F. Calories per oz. Protein G. Calories per oz. Fat H. Calories per oz. Carbohydrate I. Calories per oz. Total