thick, and rather furry on the inner side. The second pair are furry on the outer side, and especially on the edges. The third pair still more so.

The outer scales are not dead, like those of so many trees, but increase more or less in size. The dark colour is due to a layer of black, more or less angular bodies, which are flattened hairs, containing a dark resinous secretion, and do not increase in size or number. As the scale grows they are, therefore, carried further and further apart, and occupying a smaller relative portion of the surface, the general colour becomes lighter and greener.

HORSE CHESTNUT (Esculus)

The

The bud of the Horse Chestnut (Esculus Hippocastanum) is protected by eight or ten scales. outer ones are dark brown and short; they are serially continuous with the leaves of the preceding year. Those following become gradually longer and paleroften pinkish towards the end. The inner ones have a delicate fringe along their edges. The outside of the bud is very sticky. The scales are followed by normal leaves. Each segment of the leaf is conduplicate, and the midribs of the first, as well as the petiole and the internodes, are further protected by a thick felt, which is sometimes of a rich orange colour. This is less developed on the inner leaves, where it would not be so much wanted.

PROTECTION BY LEAF-BLADE

LILAC (Syringa)

The bud of a Lilac (Syringa vulgaris) at first sight closely resembles that of a Maple or Horse

FIGS. 166-172.-LILAC, SHOWING SEPARATED BUD-SCALES. Enlarged. Chestnut, but the real structure is quite different. Each scale here represents a leaf-blade. The first pair (fig. 166) are short and broad; the second (fig. 167) are somewhat longer and pointed; the third

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(fig. 168) are longer than broad; the fourth (fig. 169) still longer, and rather narrowed at the base; the fifth (fig. 170) begin to assume the form of the leaf, and have a distinct, though very short, base; the sixth and seventh (figs. 171, 172) approximate still more to the final form of the leaf.

In the Holly also (Ilex Aquifolium) the bud-scales are leaf-blades.

THE WILLOW (Salix)

The winter-buds of the Goat Willow (Salix Caprea) are ovate, obtuse, tumid, relatively short, and more or less downy. The terminal bud dies, so that growth is renewed by the lateral ones. The bud is covered by a cap or scale in one piece, which shows no line of cohesion on either the anterior (fig. 173) or posterior face (fig. 174). Laterally, however, there are two strong ribs or keels, one on each edge. When growth recommences in spring the scale splits regularly from apex to base on the posterior face, and from the apex downwards, for one-third to one-half its length, on the anterior face (fig. 175). If the scale splits further, it does so irregularly. The whole scale, flattened out at fig. 176, shows the extent of the natural splitting, and also the two ribs or keels. This method of splitting and the two ribs indicate that the scale of the winter-bud is composed of two leaves, inserted right and left on the axis and cohering

by their anterior and posterior edges. The first leafblade (fig. 177) is roundly ovate, obtuse, densely silky on the back and edges, and thinly hairy on the inner face. The second and third leaf-blades are oval-oblong, obtuse, and narrower. The fourth is oblong and more narrowed to the base. sixth and seventh are

The fifth is lanceolate; and the very similar. The eighth leaf

FIG. 173.-Portion of shoot with a lateral bud; s, scar of fallen leaf; s.st., scar of fallen stipule.

FIG. 174.-Posterior view of the same bud.

FIG. 175.-Anterior view of another bud bursting, showing the silky leaves, 1, 1; w.s., winter-scale.

FIG. 176.-Another view of the same scale removed and spread out, showing two midribs, m, m; a.e., anterior edges, slit naturally; p.r., posterior edges, slit to the base naturally on the bursting of the bud.

blade is more decidedly narrowed to the base, and when in situ is more completely rolled round the bud than the previous ones, almost entirely covering it. It will be seen that there is little difference between the lengths of the first eight leaf-blades. The ninth, tenth, and eleventh leaves are very similar to the

eighth, but much shorter and smaller. The stipules are large, particularly on the leafy shoots; but they develop after the leaves are expanded, or during that process. Some forms are exstipulate.

The winter-buds of the White Willow (Salix alba) are all axillary; the terminal one, as well as the tip of every shoot, dies. The buds are oblong, obtuse or subacute, compressed antero-posteriorly, but tumid on the

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178

179

180

181

182

183 184

185

SALIX ALBA.

FIG. 178.-Anterior aspect of winter-bud covered with one scale.

FIG. 179.-Posterior aspect of the same, showing the median thickened suture, s.
FIG. 180.-Scales of winter-buds bursting along the suture on the posterior aspect,
showing the mass of leaves, 7, bent at the apex.

FIG. 181. First true leaf, immediately inside the winter-scale.

FIG. 182.-Second leaf.
FIG. 185.-Tenth leaf.

FIG. 183.-Fifth leaf.

FIG. 184.-Eighth leaf.

anterior face (fig. 178), thickened at the edges, and have a thickened suture (fig. 179) along the middle of the posterior aspect. The cap-like scale seems to consist of two leaves united; its thickened edges and the strong, slightly branched nerve, easily seen on the inner face of these thickened edges, tend to support this view; but no suture is discernible on the anterior face. When growth recommences in spring, the scale bursts along the suture on the posterior face (fig. 180).