the fields, and the forest, but in a restricted sense, as it will be used here, it is applied to the class of orchard products represented by apples, peaches, pears, etc. Fruits, in a general sense, include also that class of wild or cultivated edible bodies known as berries. The term "berry" is restricted in its present sense to the products of certain small shrubs or vines, such as gooseberries, blackberries, raspberries, etc. The fruits that grow upon small bushes, such as the currant and gooseberry, occupy an intermediate position between the orchard fruits which have been mentioned and berries. Orchard fruits are conveniently divided into large and small fruits, the large fruits being represented by the apple, pear, peach, quince, etc., and the small fruit by the cherry and plum. Fruits were doubtless among the earliest foods of man, and this leads to another classification of fruits, namely, wild and cultivated. Wild fruits, at the present time, do not include any large proportion of human foods. There are certain trees growing wild, such as the mulberry, the wild cherry, and others, which produce delicious fruits, usually of small size. The term "fruit" as used herein does not include that very valuable class of foods known as nuts, which is considered under a separate classification.
General Characteristics of Fruits.—The general characteristics of fruits include their color, flavor, odor, and nutritive properties in so far as we are concerned with them in this manual. They are composed very largely of water, perhaps 80 percent or more. The solid matter consists of the usual cellulose structure of vegetable bodies, sugars, gums, organic acids, and mineral matters. Fruits are all succulent, that is, by reason of their high content of water, composed chiefly of matters in solution which constitute their juices. All fruits, therefore, when subjected to pressure yield a juice which contains the principal portion of their dietetic constituents. The study of the composition of the fruit juices would, therefore, naturally accompany a study of the fruits themselves. The chief characteristics of fruit from a dietetic point of view and also a palatable standpoint are their sugars and acids. The characteristic of taste depends on these two constituents principally. In addition to this, the fruits contain aromatic substances belonging to the class of essential oils and compound ethers which give to them the agreeable odor which adds so much to their value. Fruits are naturally colored and these colors, to which the eye is accustomed, become marks of distinction and excellence in many cases. The prevailing colors of fruits are red, yellow, and green. All shades of colors, however, are represented by the mingling of the primary tints. Certain colors are associated with certain fruits as, for instance, red with the cherry, raspberry, etc., green, red, and yellow with apples, and shades of red and yellow with peaches. These colors are due to the different conditions of the chlorophyll or vegetable coloring matter which the skin of the fruit contains. The three principal color tints which are produced are
