NATURAL SELECTION 6S 



fectly adapted to each other and to the physical conditions under 

 which they live, that none of them could be still better adapted or 

 improved; for in all countries the natives have been so far con- 

 quered by naturalized productions that they have allowed some 

 foreigners to take firm possession of the land. And as foreigners 

 have thus in every country beaten some of the natives, we may 

 safely conclude that the natives might have been modified with 

 advantage, so as to have better resisted the intruders. 



As man can produce, and certainly has produced, a great result 

 by his methodical and unconscious means of selection, what may 

 not natural selection effect? Man can act only on external and 

 visible characters; Nature, if I may be allowed to personify the 

 natural preservation or survival of the fittest, cares nothing for 

 appearances, except in so far as they are useful to any being. She 

 can act on every internal organ, on every shade of constitutional 

 difference, on the whole machinery of life. Man selects only for 

 his own good; Nature, only for that of the being which she tends. 

 Every selected character is fully exercised by her, as is implied by 

 the fact of their selection. Man keeps the natives of many climates 

 in the same country. He seldom exercises each selected character 

 in some peculiar and fitting manner; he feeds a long and a short- 

 beaked pigeon on the same food; he does not exercise a long- 

 backed or long-legged quadruped in any peculiar manner; he ex- 

 poses sheep with long and short wool to the same climate; does 

 not allow the most vigorous males to struggle for the females; he 

 does not rigidly destroy all inferior animals, but protects during 

 each varying season, as far as lies in his power, all his productions. 

 He often begins his selection by some half-monstrous form, or at 

 least by some modification prominent enough to catch the eye or 

 to be plainly useful to him. Under nature, the slightest differences 

 of structure or constitution may well turn the nicely balanced 

 scale in the struggle for life, and so be preserved. How fleeting are 

 the wishes and efforts of man! How short his time, and conse- 

 quently how poor will be his results, compared with those accumu- 

 lated by Nature during whole geological periods ! Can we wonder, 

 then, that Nature's productions should be far "truer" in charac- 

 ter than man's productions; that they should be infinitely better 

 adapted to the most complex conditions of life, and should plainly 

 bear the stamp of far higher workmanship? 



It may metaphorically be said that natural selection is daily 

 and hourly scrutinizing, throughout the world, the slightest varia- 

 tions; rejecting those that are bad, preserving and adding up all 

 that are good; silently and insensibly working, whenever and 



