Some grape-growers attach considerable importance to the direction in which rows run, holding either that the full blaze of the sun at mid-day is desirable for vine, soil and fruit, or that it is detrimental. Those who desire to provide fullest exposure to the sun plant rows east and west when the distance between vines is less than the distance between rows; north and south when vines are farther apart in the row than the rows are from each other. When shade seems more desirable, these directions are reversed. Most often, however, the rows are laid out in accordance with the shape of the vineyard; or, if the land is hilly, the rows follow the contour of the declivities to prevent soil erosion by heavy rains. _Alleys._ For convenience in vineyard operations, especially spraying and harvesting, there should always be alleys through a vineyard. On hilly lands, the alleys are located to secure ease in hauling; on level lands they are usually arranged to cut the vineyards into blocks twice as long as wide. An alley is usually made by leaving out a row of vines. Many vineyards are laid out with rows far enough apart so that alleys are not needed. _Distances between rows and plants._ There are great variations in the distances between rows and plants in different regions, and distances vary somewhat in any one region. Distances are influenced by the following considerations: Rich soils and large vigorous varieties require greater distances than poor soils and less vigorous varieties; sometimes, however, it is necessary to crowd a variety in the vineyard so that by reducing its vigor fruitfulness may be promoted. Usually the warmer the climate, or the exposure, the greater should be the distance between vines. Very often the topography of the land dictates planting distances. But while taking in account the preceding considerations, which rightly suggest the distances between plants in the row, convenience in vineyard operations is the factor that most often fixes the distance between rows. The rows must be far enough apart in commercial vineyards to permit the use of two horses in plowing, spraying and harvesting.