All these improvements, and others of a similar kind, may be effected without the addition of new plants; but the greatest addition to natural woody scenery consists in introducing, among the native plants, such exotic kinds of trees and shrubs, and especially evergreens, as are suitable to the soil and locality. Hence the immense improvement that has been made in natural woods by the introduction of rhododendrons, common and Portugal laurels, mahonias, box, holly, junipers, and similar evergreens, as substitutes, in part or wholly, for the native undergrowths, which are chiefly deciduous. It is not an easy matter to introduce plants of deciduous trees and shrubs, of any kind, into natural woods or plantations already advanced so far as to be 20 or 30 feet in height, because young deciduous plants require much more light than young evergreens: but deciduous trees may frequently be budded standard high on trees already growing there; for example, in every part of the country there are common thorns, sycamores, oaks, elms, and ashes, and on these some scores of kinds might be budded or grafted. At all events, this might be done with upwards of sixty distinct sorts of thorn, plants of which can be purchased from the nurserymen, or cuttings obtained from the Horticultural Society; and nothing can be more ornamental on the outskirts of a plantation, whether when they are in blossom, in May, June, and July, or in fruit, red, black, green, or yellow, from July to Christmas. All the natural woods at Corehouse abound in wild herbaceous plants; and in early spring the primrose, and afterwards the wild hyacinth, the stellaria, and the foxglove, form fine masses of colour: but the effect of the numerous wild plants here has been increased, to a degree which the botanist alone can value, by planting and sowing among them many kinds of perennials and annuals, including the hardier bulbs. The artificial plantations, formed where no trees grew before, have made extraordinary progress, in consequence of the soil being naturally good and being deeply trenched; but, like most others in this part of the country, they have not been sufficiently thinned out and pruned.