38 



METHODICAL SELECTION. [Chap. L 



berries differ in size, colour, shape, and hairiness,, and 

 yet the flowers present very slight differences. It is 

 not that the varieties which differ largely in some one 

 point do not differ at all in other points; this is hardly 

 ever,— I speak after careful observation,— perhaps 

 never, the case. The law of correlated variation,, the 

 importance of which should never be overlooked, will 

 ensure some differences; but, as a general rule, it can- 

 not be doubted that the continued selection of slight 

 variations,. either in the leaves, the flowers, or the fruit, 

 will produce races differing from each other chiefly in 

 these characters. 



It may be objected that the principle of selection has 

 been reduced to methodical practice for scarcely more 

 than three-quarters of a century; it has certainly been 

 more attended to of late years, and many treatises have 

 been published on the subject; and the result has been, 

 in a corresponding degree, rapid and important. But 

 it is very far from true that the principle is a modern 

 discovery. I could give several references to works of 

 high antiquity, in which the full importance of the 

 principle is acknowledged. In rude and barbarous 

 periods of English history choice animals were often 

 imported, and laws were passed to prevent their ex- 

 portation: the destruction of horses under a certain 

 size was ordered, and this may be compared to the 

 " roguing " of plants by nurserymen. The principle of 

 selection I find distinctly given in an ancient Chinese 

 encyclopaedia. Explicit rules are laid down by some 

 of the Eoman classical writers. From passages in 

 Genesis, it is clear that the colour of domestic animals 

 was at that early period attended to. Savages now 

 sometimes cross their dogs with wild canine animals, 



