the country where wheat has deteriorated, distinguish carefully between the flour-producing qualities of wheats from various sections and fix the price accordingly. Even in the household, information concerning the real nutritive value of various foods is being sought eagerly, and foods let down to possess the highest value in the maintenance of life are displacing, even at a higher cost, the inferior products. The quality valuation is, in fact, being extended as rapidly as the growth of knowledge will permit to the chief food materials of commerce. As this practice becomes fixed the dry-farmer will be able to command the best market prices for his products, for it is undoubtedly true that from the point of view of quality, dry-farm food products may be placed safely in competition with any farm products on the markets of the world. Proportion of plant parts It need hardly be said, after the discussions in the preceding chapters, that the nature of plant growth is deeply modified by the arid conditions prevailing in dry-farming. This shows itself first in the proportion of the various plant parts, such as roots, stems, leaves, and seeds. The root systems of dry-farm crops are generally greatly developed, and it is a common observation that in adverse seasons the plants that possess the largest and most vigorous roots endure best the drouth and burning heat. The first function of the leaves is to gather materials for the building and strengthening of the roots, and only after this has been done do the stems lengthen and the leaves thicken. Usually, the short season is largely gone before the stem and leaf growth begins, and, consequently, a somewhat dwarfed appearance is characteristic of dry-farm crops. The size of sugar beets, potato tubers, and such underground parts depends upon the available water and food supply when the plant has established a satisfactory root and leaf system. If the water and food are scarce, a thin beet results; if abundant, a well-filled beet may result.