CH. X.] NATURAL SELECTION, 18 



those individuals which are fleetest, strongest, most sagacious, 

 lious with supplest muscles, moths witii longest antennae, 

 moUusks with hardest shells, wolves with keenest scent, bees 

 with surest instinct, flowers with sweetest nectar, — until, in 

 the tjourse of untold ages, the numberless varieties of organic 

 life have been produced by the same process of which man 

 now takes advantage in order to produce variations to suit 

 his own caprices. 



Between natural selection and selection by man there is, 

 however, one important difference. Selection by man tends 

 to produce varieties adapted to satisfy human necessities or 

 inclinations, and it has no direct reference to the maintenance 

 of the species. Such abnormities as the pouter and tumbler 

 pigeons could not be sustained in a state of nature ; and 

 hence, when domesticated animals are turned loose, they are 

 apt to revert to something like their ancestral type,^ else they 

 are exterminated by races better adapted to wild life. But 

 natural selection, working with the sternest of methods, saves 

 from the general slaughter only those individuals which can 

 best take care of themselves, and thus maintains each species 

 in adaptation to its environment. The wonderful harmonies 

 in the organic world, which a crude philosophy explained as 

 the achievement of creative contrivance, are therefore due to 

 the continued survival of the fittest and the continued 

 slaughter of the less adapted plants and animals. 



Now if the geography and meteorology of the earth were 

 ever-constant, if the nature of the soil, the amount of 

 moisture, the density of the atmosphere, and the intensity of 

 solar radiance were everywhere to remain forever unaltered, 

 and if each race of plants and animals were always to remain 

 confined to one limited area, the survival of the fittest would 

 simply maintain unaltered any given aspect of the beings 

 constituting the organic world. All variations on either side 



1 This fact, wliich has often been alleged by superficial critics as an obstacle. 

 to the Darwinian theory, is thus in reaJity implied by that theory. 



