The habit of growth of a variety has much to do with its pruning. Some varieties of apples are upright, others are spreading growers. Climate and locality greatly affect these habits of growth. So also the habit of a young tree often differs from the habit of the same tree in old age. The tendency is for a tree to continue its growth from its uppermost or terminal buds. Although the heading in of new growth checks this upward tendency and throws the energy of the tree into the development of lateral and dormant buds, nevertheless the pruned tree soon resumes its natural upward growing habit. Plant food is taken up by the minute tree rootlets in solution and carried to the leaves where it is elaborated and then returned for use to the growing tissues of the tree. Whenever there is any obstruction above a bud the tendency is to throw the energy of the branch into a lateral bud, but if the obstruction is below the bud the branch merely thickens and growth is checked. When too heavy pruning is practiced the balance between the roots and top is disturbed. This usually results in what are commonly known as "suckers." These are caused by an abnormal condition and while they may be the result of disease or injury to the tree, they are often of great value in restoring or readjusting the proper balance between the roots and top. Pruning a tree is a way of thinning the fruit and a good one. It may sometimes be used to influence the bearing year of trees like the Baldwin, which have an alternate bearing habit, but this is a more theoretical than practical method. Fruit bearing is determined more by the habitual performance of the tree than by any method of pruning, and this is especially true of old trees. It is easier to influence young trees. Conditions which tend to produce heavy wood growth are unfavorable for the formation and development of fruit buds. A quiescent state is a better condition for this. REASONS FOR PRUNING.--With these fundamental principles in mind we may safely outline a method of pruning an apple tree. As the desired end is different so will the method of pruning a young tree differ from that of an old one. There are five important things for which to prune a young tree, namely: 1. To preserve a proper balance between the top and root at the time of setting out. This usually means cutting off the broken and the very long roots to a reasonable length and cutting back from one-half to two-thirds of the growth of the previous season. 2. To make the top open in order to admit the sunlight freely. In the humid climate of the Northeastern States, it is usually advisable to prune a tree so as to have a rather open top. This is necessary in order properly to color and mature the fruit.