226 SCIENCE OF THE STUDY OF TREES. TAUT II. 



pliints, lire not many ; but, still, somo, such as the canker, &c , retiuire 

 to 111' noticed, when the species subject to them cf>me umler review. 

 J). Acriiln.ls. Some trees and shrubs are more li:ible than others to 

 be blown down, or have some of their branches broken ofl' by high 

 winils, or by the weight of snow; and these species should be pointed 

 out to the inexperienced planter. Some, also, are said to be less liable 

 to be struck by lightning tlmn others; for example, the beech. 



7. Geographical Distributioiu The dilFerent countries will be mentioned 

 where each species is found naturally ; and, where practicable, the diderent 

 localities, soil, elevation and other particulars will be given. It will also 

 be stated, as far as is known, in what countries each species is cultivated, 

 and to w .at purposes it is applied. 



8. History. This suljject may be included under two heads, viz. retro- 

 spective and prospective. 



A. The Rc/rospective HinUvij of every species or variety will commence 

 with its first discovery, or record by botanists; and its progress will be 

 traced in every country, but more espi'cially in Hritain, from that period 

 to ihe present time. Though the history of some trees and shrubs 

 commences with the time of the Romans, yet that of others is comjjara- 

 tively obscure; and, of some of tiie finest ornaments of our gardens, 

 little more can be stated than that they are races or varieties, perhaps 

 hybrids, raised by cultivators whose names are unknown. 



B. The Prospective History, or probable progress, of our knowledge of 

 species may be included under the heads of doubtful species, unnamed 

 species, and expected additions. 



a. Doubtful Species. In almost every genus, containing several species, 

 there are some of the names which are of doubtful aj)plication, which 

 under this head we shall bring together, with their autliorities, in 

 order to din-ct the attention of uotunists and cultivators to the subject. 



b. Unnamed Species. The introducti(m of new species of trees and 

 shrubs into British gardens is constantly going on, and numbers are 

 also as constantly being i aised from seed in the country. In general, 

 neither of these kinds of additions to our ligneous flora can be re- 

 ceived into books till they have flowered; when they are named, 

 figured, and recorded in some botanical work. It often hapf)ens, how- 

 ever, that the genus to which a new plant belongs is discovered, from 

 tlie general hubitof the plant, long before it has llowere.l ; and in such 

 a (;ase, lhou<:h the species may not be introduced into botanical cata- 

 logues, plants of it may be distributed among cultivators by those 

 wi"io liave introduced it, and it may be projiagated for sale in the 

 nurseries, under son.e provisional name. Such species, and also 

 varieties raised in the country from seed, or otherwise procured, de- 

 serve notice in a work like the present, and we shall devote this head 

 to the subject. 



0. Expected Additions. The species of some genera are so numerous, 

 anil their geographical distribution is so extensive, that from these 

 circumstances"al(me we may reasonably anticipate the discovery and 

 tiie introduction of a'tditioiiai species. Of other genera, many species 

 suitable for our climate, though not yet introduced, have been de- 

 scribed bv botanists as indigenous in dilFerent parts of the temperate 

 hemispheres. It will be useful to direct attention to both these 

 points, with a view of stimulating travellers and others to procure the 

 additional species that are known ; and wealthy individuals, or societies 

 or associations, to send out collectors to discover those species which 

 may be yet unknown. 

 9. Use. Trees and shrubs tire used in the arts of construction, of machinery, 



and of fabrication ; in tiie chemical arts of dyeing and colouring ; in 



domestic and rural economy ; and in med'cine. 



A. The Arts of Construction arc, civil, military, and marine architecture; 

 engineerii'g, carpenti y, joinery, cabinet-making, carving, and uuKlelling ; 



