Darwin s Artificial and Natural Selection 99 



comparison with the leaves and flowers of the same set of 

 varieties. 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, 

 color, 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 

 importance of which should never be overlooked, will insure 

 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." 



Exception may perhaps be taken to the concluding sen- 

 tence, for, interesting as the facts here recorded certainly 

 are, it does not necessarily follow that all domestic products 

 have arisen "by the continued selection of slight variations," 

 however probable the conclusion may appear. Darwin also 

 believes that a process of "unconscious selection" has given 

 even more important " results than methodical selection." By 

 unconscious selection is meant the outcome of "every one 

 trying to possess and breed from best individual animals." 

 "Thus a man who intends keeping pointers naturally tries 

 to get as good dogs as he can, and afterwards breeds from 

 his own best dogs, but he has no wish, or expectation of per- 

 manently altering the breed. Nevertheless we may infer 

 that this process, continued during centuries, would improve 

 and modify any breed. . . . There is reason to believe that 

 the King Charles spaniel has been unconsciously modified 

 to a large extent since the time of that monarch." 



The enormous length of time required to produce new 

 species by the selection of fluctuating variations is every- 

 where admitted by Darwin ; nowhere perhaps more strikingly 



