with alternate parallel branches proceeding to the margins, crossing veinlets and a reticulating network of venules,—can be plainly traced on its under side. The ultimate autumnal colour of the Willow leaves is yellow or orange; but the gradations of tint, from the normal green to the final hue, present oftentimes very beautiful contrasts. Minute spots of rich, golden orange, overspreading the decaying green, produce an almost bronze tint in some leaves. In others the whole of one side will be orange whilst the other is green; or the top or the bottom may be yellow, golden brown, or orange, and the rest of the surface green or green spotted with yellow or orange. Pretty effects are produced when an orange leaf is freckled with tiny green spots, as also when a green leaf is freckled with yellow or orange. But all these changes, and many more, can only be noted on close examination. The smooth, oval, unindented leaf of the Alder Buckthorn bears a not altogether remote likeness, in the character of its venation, and of its autumn tinting to that of the Willow we have described and figured. The principal veins sweep upwards from the mid-vein, in curves, towards the margins on either side and are very prominently shown on the under side. Across these, smaller veins run enclosing tissue which is traversed by a fine network of venules. The final colour of the Alder Buckthorn is a deep yellow, or orange; and these tints, commencing sometimes upon the edges of the leaves, sometimes at their tops and sometimes on either side, will advance upon the normal hue in an almost endless variety of ways, giving occasion for many beautiful effects of contrast. |