218 



SCIENCE OF THE STUDY OF TREES. 



PART ir< 



all aboriginal species must be decidedly distinct, so we think it practicable to 

 render this distinctness so obvious, in the few words which constitute a 

 specific character, that the name of a plant may be discovered by it. To recur 

 to the genera jPraxinus and C'ratag^gus, we will ask any botanist, whether 

 practical or theoretical, whether, from the specific characters of the botanical 

 species of i^. americana or of (7. Oxyacantha, he could discover the individuals 

 to which those names are intended to apply, -without having recourse to dried 

 specimens or engravings ? We ask the same question with reference to most 

 of the alleged species of >S^lix, f/'lmus, Quercus, Pinus, and i2ubus. We 

 admit that many of these botanical species, or vai'ieties, as we consider them, 

 maybe made out from lengthened descriptions j but we deny the practicability 

 of doing this, in many cases, from short specific characters. That we may not 

 be misunderstood, we refer more particularly to the genera Quercus, >S'alix, 

 c^'^lmus, and iiubus ; and even to Tiha. 



But, though we question the utility of specific characters to botanical species 

 as such, we are of opinion that they may be of some use when ajaplied to these 

 species as being varieties of an aboriginal species, and indicating that they are 

 such. For example, in the case of the specific character of jPraxinus 

 pubescens, caroliniana, lancea, &c., as absolute species, and to be compared 

 with different botanical species of the same aboriginal species, and also of 

 F. excelsior, we think it would be extremely difficult, if not impossible, to 

 apply them ; but, if it were known that these botanical species were only 

 varieties of F. araericana, the difficulties of distinguishing them would be 

 greatly diminished. For this reason we shall, in many cases, adopt the specific 

 characters of botanical species given by botanists, adding to them such de- 

 scriptive particulars as our own observation has enabled us to supply. 



We may here refer to two causes, which have not only contributed to the 

 great im.perfection of the specific characters of botanical species ; but which 

 have been the means of multiplying the number and descriptions of these spe- 

 cies in books, to an extent which, we are persuaded, does not exist in natnre. 

 One of the practices to which we allude is, that of describing species from dried 

 specimens only; and the other, that of mistaking varieties for species by col- 

 lectors. We admit that the first of these pi-actices is unavoidable in the infant 

 state of botanical science; and that it must necessarily be continued, till 

 botanists shall rise up in every country in such numbers, and of such acquire- 

 ments, as to be able to describe the plants of every country from nature; or 

 till all the species, or all the alleged species, of every genus of plants shall be 

 assembled together in one spot, and what are really aboriginal species shall be 

 determined, after observing them for a series of years. Happily, both these 

 results are in progress of attainment : botanists are beginning to spring up 

 in every civilised country, or to emigrate from old, and settle in newly dis- 

 covered countries ; and, in all the wealthiest governments of Europe, assem- 

 blages of plants are being made in botanic gardens. If the directors of 

 these gardens were to cooperate, and each to undertake the collection and 

 the study of one or more genera of hardy plants, we should, at no distant 

 period, be able to say what are really species, and what are not. If botanic 

 gardens were established in every country and climate of the world, and the 

 whole of the directors of these gardens were to act in concert (which concert, 

 being quite distinct from political associations, would not be objected to by 

 any government), in each garden might be assembled all the alleged species or 

 varieties of at least two or three genera, those being selected for which its 

 climate, situation, soil, and extent were most suitable; and, after a few years, 

 the aboriginal species, and the more prominent varieties, might be determined 

 on. In the meantime, this process might be commenced in many of the 

 botanic gardens akeady estaWished in the temperate regions of the world ; and 

 we have already shown (p. 192.) how, in every country in these regions, the 

 determination of species, and their nomenclature, might be effected, as far as 

 respects hardy trees and shrubs. 



When the natural system of botany comes to be more generally understood 



