INTKODUCTION. 



5 



Part III., which will form our next division, and that, indeed, 

 which will comprise by far the greater part of the Work, will be 

 the history and description of the different species and vari- 

 eties of trees and shrubs, whether native or indigenous, useful 

 or ornamental, at present cultivated in Britain. 



We shall add to the perfectly hardy species the names, and 

 short descriptive paragraphs, of some ligneous plants, which have 

 been found by cultivators to be half-hardy in the climate of Lon- 

 don ; and of others, which, from their native countries and habits, 

 we think not unlikely to prove so. We make this addition to 

 the Arboretum et Fruticetum Britannicum for two purposes: 

 in the first place, because, by trying species from all countries in 

 the open air, some hitherto kept in hot-houses or green-houses 

 may be found quite hardy ; such having been the case^ with 

 Kerrm japonica, Cydonia japonica. Hydrangea Hortensm, 

 v4z/cm6« japonica, and a number of others. We may add, also, 

 that, though the nature of a species cannot be so far altered as 

 to fit an inhabitant of a very hot climate for a cold one, yet that 

 the habits of individuals admit of considerable variation, and 

 that some plants of warm climates are found to adapt them- 

 selves much more readily to cold climates than others. Thus, 

 the common passion flower, according to Dr. Walker, when 

 first introduced into the Edinburgh Botanic Garden, lost its 

 leaves during winter ; but, in the course of a few years, the same 

 plant retained the greater part of them at that season. The 

 same author relates that plants of the common yew, sent from 

 Paris to Stockholm to plant certain designs by Le Notre, laid 

 out there for the king of Sweden, all died, though the yew is 

 a native of the latter country, as well as of France. 



Every gardener must have observed that the common weeds 

 which have sprung up in pots, in hot-beds or in hot-houses, when 

 these pots happen to be set out in the open air during winter or 

 spring are killed, or have their leaves injured ; whilst the same 

 species, which have sprung up in the open ground, are growing 

 around them in a flourishing condition. 



The obvious conclusions from these facts are, that the habits 

 of plants admit of a certain degree of change with regard to the 

 climate which they will bear ; that the degree in which this power 

 exists in any plant is only to be ascertained by experiment ; 

 and that the only mode of making these experiments is, by trying 

 in the open air plants usually kept under glass. There is reason 

 to believe, from trials already made, that many of the trees and 

 shrubs of Australia, and particularly those of New Zealand and 

 Van Diemen's Land, will ultimately become so habituated to the 

 cHmate of London, as to Hve through the winter against a wall, 

 with scarcely any protection. 



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