10 INTRODUCTION. 



our most valuable plants, whether in agriculture, horticulture, 

 or floriculture, are more or less indebted for their excellence 

 to art. Our cultivated fruit trees are very different from the 

 same trees in a wild state; and our garden and field herbaceous 

 vegetables so much so, that, in many instances, not even a 

 botanist could recognise the wild and the cultivated plant to be 

 the same species. There is reason to believe that the same 

 means by which we have procured our improved varieties of 

 fruit trees will be equally effective in producing improved varie- 

 ties of timber trees. A few species, such as the oak, the elm, 

 the mao-nolia, &c., have had improved varieties raised from seed 

 bv accidental crossing, or by the selection of individuals from 

 niultitudes of seedlings ; and variegated varieties, and varieties 

 with anomalously formed leaves, or with drooping or erect shoots, 

 have been procured from the sports of parts of different plants. 

 But the mode of improvement by cross-fecundation is yet quite 

 in its infancy with respect to timber trees ; and to set limits to 

 the extent and beauty of the new varieties which may be pro- 

 duced by it is impossible. There is no reason why we may not 

 have a purple-leaved oak, or elm, or ash, as well as a purple- 

 leaved beech ; or a drooping sweet chestnut as well as a drooping 

 ash. The oak is a tree that varies astonishingly by culture; 

 and, when the numerous American varieties that have been 

 introduced into this country shall have once begun to bear seed, 

 there is no end to the fine hybrids that may be originated be- 

 tween them and the European species. In short, we see no 

 difficulty in improving our ornamental trees and shrubs to as 

 oreat an extent as we have done our fruit trees and shrubs ; 

 tliou'di we are as yet only procuring new species from foreign 

 countries, which may be considered as the raw material with 

 which we are to operate. 



Part IV., which will form the last division of the Arboretum 

 et Fridicetnm Britafniiaim, will be devoted to selected lists of the 

 trees and shrubs described, classified according to their different 

 capacities for fulfilling the various purposes for which trees and 

 shrubs are recjuired by the planter and by the landscape-gar- 

 dener. For the rest we refer to the Table of Contents. 



The utility of such a Work as the Arboretum et Fruticetum 

 Britajinicum to the gardening world, and to the landed jh'o- 

 prietor, will not, we think, be questioned. We shall say nothing, 

 therefore, of the influence which it cannot fail to have in pro- 

 moting a taste lor the culture and spread of such foreign trees 

 as we have already in the country ; and in exciting a desire for 

 introducing others from different parts of the world, and for 

 orii,'inating new varieties by the different means employed by 

 art lor tiiai purpose. One remark, however, we may be per- 

 mitted to make on the use of such a Work as the Arboretum et 

 Fruticcliim Briiannicum to gentlemen of landed properly. Every 



