561. If we consider trees and shrubs no longer under the relation of the colour of their flowers, but with regard to the manner in which we may employ their foliage in the decoration of gardens, we shall perceive that there is only a very small number of contrasts of scale and hue which we can realize while vegetation is active; yet in autumn, when plants, losing their leaves before falling, assume various colours, as red, rose, scarlet, orange, and yellow, these, by their brilliancy, recall the season of flowers. Most trees and shrubs present, in the summer season, only the green of their foliage; and, although this green varies in tone and hue, the differences are always trifling. 562. _Harmonies of Contrast._—The most decided contrast of colour that we can establish between the leaves of ligneous plants, is that of green, with foliage nearest to red. But even the _purple beech_ is more of a red-brown than a dark _red_, properly so called, for the colour of leaves results from a mixture of red and green, which, according to the principle of mixing colours must produce black, if they are in suitable proportion, or a brown tone of the green or red scale, according as one or the other colour predominates. The contrast of hue is established by the assortment of a bluish-green and a yellowish green of tones unequally high, by the contrast of a bluish-green brown with a yellowish light green, &c. 563. _Harmonies of Analogy._—Nearly all the masses of various trees in our landscape gardens present certain harmonies of hues mostly resulting from associations established according to considerations foreign to those of the assortment of foliage—an evident result, remembering (561) that the colours of the leaves of the greater part of plants are of green belonging to scales more or less allied, and of tones but little distant from each other. (_a_) Harmonies of analogy of hues formed of allied tones belonging to neighbouring scales, are those which it is least difficult to obtain. (_b_) Arrangements of foliage presenting a series of equidistant tones of the same scale of green. ON THE DISTRIBUTION AND PLANTING OF TREES, ETC., IN MASSES.