Evenness in the soil on the surface is important when it is so retentive that water may collect in the depressions after heavy rain. In such places the plants are much liable to fail, especially in the early winter, or even shortly after they may have begun to grow, if moisture is excessive. In order to smooth and even the land sufficiently, it may be necessary to run over it some form of leveller. This does not mean, however, that it will not be necessary sometimes to plow the land in ridges, or "lands," as they are sometimes called, but it does mean that the slope from the center of the lands toward the furrows shall be even and gradual, in order that an excess of surface water, as in rainy climates, shall be carried away by the latter. Firmness in the seed-bed is necessary chiefly to prevent too much drying out near the surface in dry weather, and the holding of too much water in the spaces between the particles near the surface in wet weather, followed by freezing of the soil. The less deep the stirring of the cultivated portion when preparing it, the longer the interval between such stirring and the sowing of the seed, and the heavier the pressure when rolling, the more firm will the seed-bed be. The deeper the land is plowed, therefore, the longer should be the interval before it is sowed, but ample rainfall will shorten this period. Firmness in the seed-bed is more important, relatively, in summer or early autumn when evaporation from the surface soil is the most rapid. On some soils of the Middle States which border on the Mississippi, the early sown autumn crop will sometimes perish after the plants have grown some distance above the ground, because of want of firmness in the soil; hence, in such locations harrowing the surface of the ground thoroughly may sometimes be a more suitable preparation than plowing and harrowing. Friability in the seed-bed is important when the soils are heavy. The influences which promote it are the presence of humus, liberal cultivation, and sometimes weather influences, as rain and frost. Unless heavy clay soils are brought into this condition, the roots of the alfalfa will not be able to penetrate the soil quickly enough or deeply enough in search of food.