NATURAL SELEOTION. 77 



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 fit- 

 ting 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 exposes 

 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 selec- 

 tion bv some half -monstrous form, or at least by some mod- 

 ification prominent enough to catch the eye or to be 

 plainly useful to him. Under nature, the slightest differ- 

 ences 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 consequently how poor will be his 

 results, compared with those accumulated by Nature 

 during whole geological periods! Can we wonder, then, 

 that Nature's productions should be far "truer" in char- 

 acter 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 workman- 

 ship? 



It may metaphorically be said that natural selection 

 is daily and hourly scrutinizing, throughout the world, the 

 slightest variations; rejecting those that are bad, preserv- 

 ing and adding up all that are good; silently and insen- 

 sibly working, 'whenever and wherever opportunity offers, 

 at tlie improvement of each organic being in relation to its 

 organic and inorganic conditions of life. We see nothing 

 of these slow changes in progress, until the hand of time 

 has marked the lapse of ages, and then so imperfect is our 

 view into long-past geological ages that we see only that 

 the forms of life are now different from what they formerly 

 were. 



In order that any great amount of modification should 

 be effected in a species, a variety, when once formed 

 must again, perhaps after a long interval of time, 

 vary or present individual differences of the same favorable 

 nature as before; and these must again be preserved, and 



