The first pruning,--except removing suckers from those in the nursery rows,--will be the heading back of the main or central stem to a hight of two or three feet, for the purpose of laying the foundation, as it were, of the head of the future tree. Three or four of the larger branches, which will push out from near the top of the severed main stem, are to be selected to form the top, and all others removed. Small lateral branches or twigs will spring out from the larger or main ones, and in this way the head of a bearing tree is formed. But before attempting to prune a mature or fruitful tree, we must consider the mode of fructification, for the filbert does not bear nuts on the young growth of the season, as in the chestnut, but on the small branchlets or spur-like twigs of the preceding season, or, as we may say, on the one-year-old twigs. The small fruiting twigs are seldom more than four to six inches long, and sometimes almost every well-developed bud on these contain pistillate flowers and embryo nuts, either singly or in clusters. In pruning the bearing trees, the main point to be observed is to head back the strong leading shoots, to prevent the trees growing too tall, as well as to force out the side or lateral twigs as fruiting wood for the ensuing year. If the heads of the trees become too much crowded to admit light and air to the center, some of the larger branches must be removed entire. The best time to prune is in early spring, when the trees are in bloom, for at this season we can readily determine the injured from the sound male catkins, and preserve enough of these to insure perfect fertilization. It is not necessary, however, that there should be healthy pollen-bearing catkins on every tree in an orchard, for if one in a dozen is well supplied, there will be sufficient to fertilize the flowers of all growing near by. It often happens, in our rather severe climate, that the catkins of some trees or varieties are winterkilled, while the pistillate flowers enclosed in the buds escape injury, and when this occurs it is well to have some hardy variety at hand, from which pollen can be obtained when needed. The inferior varieties are usually the most hardy, and the wild European hazel or our northern beaked hazel, will usually escape injury where all the large improved sorts fail, and it requires but a few minutes' labor to cut branches bearing sound catkins, and scatter these about through the heads of trees requiring such assistance to make them fruitful. SPECIES OF AMERICAN HAZELS.