222

SCIENCE OF THE STUDY OF TREES.

PAUT II.

such as the bark, leaves, flowers, fruit, &c., are of importance. Not only aretrees used in their different parts after being felled, but, in some cases, a partof their products is gathered yearlv; and some sorts, both of trees and shrubs,are in perpetnal use in a living state, as fences for separation or enclosure, asavenues for shade, and as belts or screens for shelter. The ornament whichtrees and shrubs afford to gardens and grounds may also be considered as animportant part of their use.

The rearing and culture of trees form an important part of their economicalhistory ; and require to be treated of, not only in the history of each individua!species, but when treating of trees collectively in plantations. The commence-ment of the process of rearing is with the gathering of the seed, or the takingoffof the cutting, or the forming of the layer; and the termination of the pro-eess of culture is with the felling of the tree, or the cutting down of the shrab.

CHAP. IV.

SUMMARY OF PARTICULARS TO BE TAKEN INTO CONSIDERATIO!;IN PREPARING THE DESCRIPTION, AND NATURAE AND ECONOMI-CAL HISTORY, OF TREES AND SHRUBS.

In the three preceding chapters we have treated of the Science of trees, aspictorial objects, or parts of general scenery; as organised beings, or botanicalobjects; and as forests or plantations, influencing the physical circumstancesof a country, and the condition of man. Our object in those chapters was,to give a general idea of the extensive nature of the study of trees; and inthe present chapter we propose to enumerate all the particulars which requireto be taken into consideration in giving the specific character, description,history, and uses of each individual species, race, or variety. These parti-culars, arranged in the order in which they will stand in the succeeding partof this work, are as follows: —

1. Classification. We shall adopt the natural System, chiefly for the sakeofaiding us in generalising on the genera and species which each order andtribe contains; and we shall refer, for the definitions of these ordersand tribes, to the writings of Professor De Candolle and Dr. Lindley,and more especially to the Prodromus of De Candolle, and Lindley’sIntroduction to the Natural System, and to his modification of that work inhis Kcy to Structural, Pkysiological, and Systematic Botany , published in 1835.

2. Genera. The genera of each order or tribe, with their characters, will begiven immediately after the general character of the order or tribe, in themanner of De Candolle, and as adopted by G. Don, in his edition of Mi-ler’s Dictionary.

3. Distinctive Characters. The species, races, or varieties, of each genuswill be enumerated immediately after the enumeration of the genera; andtheir distinctive characters will be given, with the English name, habit, co-lour of the flower, and time of flowering, and year of introduction intoBritain.

A. Identifications. These are references to some of the prineipal worksin which the same piant has been described under the same name.

B. Synonymes. These will be given to as great an extent as can be donewith certainty, or apparent advantage. Not only will the scientificsynonymes be given, but also those in common or ancient use in thiscountry, and the popular names in other countries.

C. Derivations will be given, not only of the generic and specific names,but of all the synonymes, where doing so is likely to prove either in-structive or interesting.