564. The principal object of the two following chapters is to supply a deficiency in works on gardening as to the manner of distributing and planting trees in masses, &c., the outlines of which have been previously sketched conformably with precise rules. For authors say nothing on this subject, and the embarrassment of a landowner who wishes to plant an estate already planned out, is further increased by this circumstance, that, in the majority of cases, the author of the plan of the projected garden, after having defined the lines of the plantations, indicated the places where isolated trees must be placed, designated the kinds of trees which should constitute groups, and others which must enter into the formation of masses with trees and shrubs (which he does not generally indicate), leaves the care of planting and other details to ordinary gardeners. Yet the distribution of trees and shrubs, however easy it may appear, in a piece of ground otherwise perfectly planned, contributes more than is generally supposed to the pleasure of a landscape garden, and presents also more difficulties than to allow of its being effected in a satisfactory manner, when it is abandoned, as generally happens, to chance. In fact, if, at the end of a few years, we observe the greater part of masses planted as they frequently are, we shall be struck with defects which were not at first perceptible, because we were then under the influence of the pleasure we always experience at witnessing the development of plants which have been confided to a carefully prepared soil; and besides, there are some defects which are only perceptible after a certain time, such, for example, as that resulting— 1. _From the plants being placed too near together._ 2. _From placing, in the front row, clumps which rise too high, or which lose their lower branches._ Such are the elder tree, and sumach. 565. It was after many years of lost enjoyments, through having planted without fixed rule, masses otherwise well designed in their contours, that I was led by my own experience to seek the means of avoiding similar errors in future. The rules I now give are not the result of reflection merely; they have been practised many years, and I am much deceived if those who observe them will not derive great facilities in their application, and experience from them a lively satisfaction. 566. I will now define several expressions employed to designate the different associations of plants which may form part of a landscape garden. An assemblage of trees and shrubs, occupying a large space, is termed a _forest_. But in a landscape garden a similar assemblage, or that which has been arranged to present the appearance of a vast space, is called a _wood_, if it is composed of trees and underwood; and a _park_, if it consists of trees only. [Illustration: ARRANGEMENT OF PLANTS IN LANDSCAPE GARDENING. PLATE XVIII.]