1. Magnitude. Some shrubs are high, approaching to the character of trees, as the mespilus and common hol ly ; others very low, as the butcher's broom and dwarf birch.
2. Mode of growth, including creepers, as the ivy ; clim bers, as the virgin's bower ; trailers, as the bramble ; com pact forms, as that of the arbor vita ; open airy branches, as in the tamarisk ; and singular branches, as those of the stagshorn shumach. Some as shrubs soon acquire pictur esque shapes, as the thorn, holly, and elder.
S. Evergreens, as the holly, laurel yew, laurustinus ar butus, &c.
4. Deciduous, as the guelder-rose, lilac, syringa. &c.
5. .1Vative, as the holly, privet, hazel, thorn, briar, Ste.
6. Xaturalized, as the rose, syringa, lilac, laburnum, &c.
7. Exotic, ur foreign, as the accuba, rhododendron, aza lea, &c.
The above arrangement refers to the plants as growing detached from other trees, and as nearly full grown. It is less intended to comprehend every characteristic distinc tion, than to suggest to the artist the principal light in which lie ought to view trees and shi ubs. Nor could he with confidence attempt planting, with everi such a know ledge as could be obtained from the above arrangement, completed by inserting all the names under their proper heads ; for unless he has seen the majority of the full grown trees himself, both tingly and connected in groups and masses, and is acquainted with the comparative rapi dity of their growth in different climates and soils, he can not well foresee the result of his labours, or look forward 41 with the prophetic eye of taste" to certain beauty. Of this there are numerous proofs, arising from the unjust preference given to exotics of unknown shapes and dura tion, in situations where the general form and situation of the tree, or even of one or two trees, is of the utmost con sequence to the effect of a whole. How frequently, on a lawn, or in a plantation near a house, do we sec acacias, cutleaved elders, variegated sycamores, &c. where the oak, birch, lime, or Spanish chesnut, would have produced a much more impressive general effect For the history, character, and culture of trees and shrubs in general use, see Planting and Rural Ornament. by Mr. Marshall ; Hunter's Evelyn's Sylva ; and Hanbury's com plete Body of Planting and Gardening.
We shall now proceed to consider planting, with a view to relative and natural beauty, or, in other worth, the an cient and modern style.
The first consideration is the nature of the whole or ge neral design ; and here, as in the ground, geometric forms will still prevail, and while the masses reflect forms from the house, or represent squares, triangles, or trapeziums, the more minute parts, characterized by lines rather than forms, such as avenues, rows, clumps and stars, &c. are contained in parallelograms, squares, or circles. In re gard to the parts, masses and avenues should extend from the house in all directions, so far as to diffuse around the character of design ; and as much farther in particular di rections, as the nature of the surface admits uf, the distant beauties suggest, and the character of the mansion requires. In disposing these masses, whether on a flat or irregular surface, regard.will be had to leave uncovered such a quan tity of lawn or turf, as shall at all events admit a free cir- • culation of air, give breadth of light, and display the form of the large masses of wood. Uniformity and variety as a whole, and use as well as beauty in the parts, must be kept constantly in view. Avenues, alleys, and vistas, should serve as much as possible as roads, walks, lines of fences, or screens of shelter or shade ; but where this is not the case, they should point to some distant beauties, or near artificial objects, to be seen at or beyond their termination. The outer extremities of artificial plantations may either join natural woods, other artificial scenes, cultivated lands, or barren heaths or commons.
When artificial plantations join natural woods, the ave nues, alleys, and circular glades of the former may be con tinued a certain length in the latter, so that the point where the natural wood begins, and the artificial plantation ends, may not be discoverable. In ;aid of this effect, the sort of tree which prevails in the natural scenes, should also pre vail in the adjoining parts of the artificial wood. When artificial scenes join other artificial scenes, nothing can be easier than, by the reciprocal continuation of avenues, strips, or masses, so far to unite the two seats, as to con ceal the boundaries of each, while the two mansions will thus each borrow a splendour from the other.