Our last example of the _Cupuliferæ_ is the well-known Hazel (_Corylus Avellana_), which is generally found in trimmed hedges and among the undergrowth of woods. Its bark on the trunk and larger branches is grey; but brown, hairy, and dotted with glands, on the young shoots. The leaves are roundish, slightly cordate and unsymmetrical, with a sharp apex and an irregularly-serrate edge; and, when young, are longitudinally plaited in the bud. The flowers appear before the leaves, and are mature in March or early April, but the early stages of the catkins may be observed on the tree throughout the winter, and even in the preceding autumn. The staminate catkins are pendulous, from one to two inches in length when in full bloom, and are commonly known to country children as 'lambs-tails.' They are of a bright yellow colour, and each flower has from four to eight stamens, with hairy anthers that produce abundance of pollen. The pistillate catkins are small, oval, and sessile, hardly to be distinguished from the foliage buds until they protrude their bright crimson stigmas. The minute flowers are enclosed in overlapping bracts which afterwards form the leafy cupules of the large woody nuts; and each one has a two-celled ovary and two styles. Our forest trees include three representatives of the order _Betulaceæ_--the Common Birch, the Dwarf Birch, and the Alder. The first of these, the Common Birch, Silver Birch, or Lady of the Woods (_Betula alba_), is at once recognised by its smooth, silver-white bark, which peels off in horizontal strips; its copper-brown branches; and its very slender, drooping twigs. The leaves are small, rhomboid or triangular, with an irregularly doubly-serrate margin, a sharp apex, and veins very prominent on the under side. They are also provided with long stalks which, together with the slender character of the weeping twigs, allow them to be moved by the slightest breeze. The male and female flowers are in separate catkins, the former of which may be seen on the tree throughout the winter, but do not bloom until April or May. Both are at first erect, but the staminate catkins droop as they mature, and shed abundance of yellow pollen. The flowers have three-lobed, deciduous, scale-like bracts; the male ones consist of two stamens with forked filaments; and the females of a flattened, two-celled ovary. The female catkins droop as they ripen, each one producing a large number of minute, one-seeded and broadly-winged fruits which are easily dispersed by the wind. Two varieties of this tree occur, one with the leaves and twigs covered with downy hairs, and the other with leaves of an oval-cordate form. The Dwarf Birch (_B. nana_) is a mere shrub, seldom exceeding two feet in height, and is to be found only in some of the mountainous districts of Scotland. It has rounded, crenate leaves, with short stalks; and the wings of the fruit are very narrow.