48 ORIGIN OF SPECIES 



eties. See how different the leaves of the cabbage are, and 

 how extremely alike the flowers ; how unlike the flowers of 

 the heartsease are, and how alike the leaves; how much the 

 fruit of the different kinds of gooseberries 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, — per- 

 haps never, the case. The law of correlated variation, the im- 

 portance of which should never be overlooked, will ensure 

 some differences ; but, as a general rule, it cannot 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 refer- 

 ences to works of high antiquity, in which the full impor- 

 tance of the principle is acknowledged. In rude and bar- 

 barous periods of English history choice animals were often 

 imported, and laws were passed to prevent their exportation: 

 the destruction of horses under a certain size was ordered, 

 and this may be compared to the "roguing" of plants by nur- 

 serymen. The principle of selection I find distinctly given in 

 an ancient Chinese encyclopaedia. Explicit rules are laid 

 down bj some of the Roman classical writers. From pas- 

 sages in Genesis, it is clear that the colour of domesticated 

 animals was at that early period attended to. Savages now 

 sometimes cross their dogs with wild canine animals, to im- 

 prove the breed, and they formerly did so, as is attested by 

 passages in Pliny. The savages in South Africa match their 

 draught cattle by colour, as do some of the Esquimaux their 

 teams of dogs. Livingstone states that good domestic breeds 

 are highly valued by the negroes in the interior of Africa 

 who have not associated with Europeans. Some of these 

 facts do not show actual selection, but they show that the 



