CHAP. II. CONSIDERED EOTANICALLY. 



213 



some place, or of some individual. If we look at the column, in such cata- 

 logues, which indicates the native country of the species, the difficulty is in- 

 creased rather than lessened : perhaps a native of the tropics is placed next a 

 plant from the frigid zone. In this, as in similar cases of collecting know- 

 ledge, the first step is to accumulate facts, and the second is to generalise on 

 them. Hitherto it would appear, that, as far as regards species and varieties, 

 the great object of botanists has been to increase their number, without much 

 regard to grouping them according to their relationship. It is not for us even 

 to try to remedy this evil in respect to all the species and varieties of plants; 

 but we propose to attempt to do so, in as far as respects the hardy trees and 

 shrubs of Britain. We shall notice, in succession, the subjects of species, 

 races, varieties, and variations ; and we shall then offer some remarks on 

 mules, hybrids, and what are called botanical species. 



A species is defined, by Dr. Lindley, to be " a union of individuals agree- 

 ing with each other in all essential characters of vegetation and fructification ; 

 capable of reproduction by seed, without change ; breeding freely together, 

 and producing perfect seed, from which a fertile progeny can be reared.' 

 (Introd. to Bot., p. 365.) This, we believe, is the general definition of a 

 species by botanists ; but it evidently requires some modification ; for, in the 

 case of many cultivated annual plants, the variety or race is reproduced 

 from seed ; and, consequently, if reproduction from seed were considered as 

 a certain test, red, white, woolly-eared, and smooth-chaffed wheat, would 

 be so many distinct species ; as would the different varieties of cabbage, 

 turnip, common lupine, &c. In like manner, also, the different varieties of 

 particular species of cultivated fruit trees, might be deemed species ; for it is 

 certain that seedlings from such varieties of fruit trees, when no cross fecun- 

 dation has been effected, always bear a nearer resemblance to the variety 

 which produced the seeds, than to any other variety, or to the original spe- 

 cies. The truth we believe to be, that trees and shrubs are subjected to the 

 same law, in regard to the reproduction of varieties from seed, as annual 

 plants ; though,"from the varieties of the former seldomer falling under our 

 observation, and requiring a longer time to come to maturity, we have not 

 the same opportunity of becoming sufficiently impressed with the identities 

 of their natures as to be able to generalise on them. On examining a num- 

 ber of individual trees or shrubs, raised from seed (say, for example, oaks 

 in an oak wood, or hawthorns in a hedge which has not been cut), we 

 shall not find two individuals exactly alike, either in foliage, in flower, in 

 fruit, in mode of growth, or even in" the earliness or lateness of budding, 

 flowering, ripening the fruit, or dropping the leaves. We have no doubt, 

 reasoning from the analogy of the wheat, that, if the acorns or haws of any 

 marked variety in such a^'wood or hedge as that mentioned were sown, and 

 the plants reared to maturity, they would be found (unless cross fecundation 

 had been accidcntall\- or artificiaily effected) more like the parent variety 

 than any other in the wood or hedge, just as in the case of seedlings from 

 varieties of wheat, cabbage, or fruit trees. 



These may be called cultivated varieties, or, according to De Candolle, 

 races ; but there are others, which we shall call accidental varieties that we 

 are not so certain can be continued by seed. For example, there are weeping 

 varieties of certain trees, such as the common ash ; and fastigiate varieties 

 of others, such as the Exeter elm, the Cratae'gus Oxyacantha stricta, and the 

 Lombardy poplar {P. fastigiiita), which we believe to be only an accidental 

 variety of P. nigra : these varieties, we think, would scarcely come true from 

 seed in every, or even in many, cases ; though we have no doubt they would 

 in some. Variegated trees and sh.rubs, we should suppose, woultl not always 

 come true from seed, any more than variegated annuals or bulbs ; but we 

 have no doubt that, as in the two latter cases, a certain proiiortion of the 

 progeny would be variegated in trees and shrubs, as well as in herbaceous 

 plants. The raising of seedlings from such accidental varieties then, will 

 prove that they are not entitled to rank with cultivated varieties or races. 



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