8i NATURAL SELECTION. Chap. IV. 



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 his products be, compared 

 with those accumulated by nature during whole geolo- 

 gical periods. Can we wonder, then, that nature's pro- 

 ductions should be far " truer " in character 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 be said that natural selection is daily and 

 hourly scrutinising, throughout the world, every varia- 

 tion, even the slightest ; rejecting that which is bad, 

 preserving and adding up all that is good ; silently and 

 insensibly working, whenever and wherever opportu- 

 nity offers, at the 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 long lapse of 

 ages, and then so imperfect is our view into long past 

 geological ages, that we only see that the forms of life 

 are now different from what they formerly were. 



Although natural selection can act only through and 

 for the good of each being, yet characters and structures, 

 which we are apt to consider as of very trifling import- 

 ance, may thus be acted on. When we see leaf-eating 

 insects green, and bark-feeders mottled-grey ; the 

 alpine ptarmigan white in winter, the red-grouse the 

 colour of heather, and the black-grouse that of peaty 

 earth, we must believe that these tints are of service to 

 these birds and insects in preserving them from danger. 

 Grouse, if not destroyed at some period of their lives, 

 would increase in countless numbers ; they are known 

 to suffer largely from birds of prey ; and hawks are 

 guided by eyesight to their prey, — so much so, that on 



