8 HEREDITY AND SELECTION IN SOCIOLOGY 



Out of the great number of organisms produced, only tlie fittest 

 will survive and attain maturity and reproduce themselves — 

 that is to say, those will survive which are best adapted to the 

 conditions of the struggle for existence. Take Darwin's case of 

 a wolf which preys on various animals, securing some by craft, 

 some by strength, and some by fleetness, and suppose that the 

 fleetest prey — a deer, for instance — ^had, from any change in the 

 country, decreased in numbers, or that other prey had decreased 

 in numbers, during the season of the year when the wolf was 

 most pressed for food. Under such circumstances the swiftest 

 and the subtlest wolves would have the best chance of surviving, 

 and would thus be selected.^ " It may be metaphorically said," 

 wrote Darwin, " that natural selection is daily and hourly 

 scrutinizing, throughout the world, the slightest variations — 

 rejecting those that are bad, preserving and adding up aU that 

 are good, silently and insensibly working, whenever and wher- 

 ever opportunity offers, at the improvement of each organic 

 being in relation to its organic and inorganic conditions of 

 life." 



The struggle for existence is sometimes — ^indeed, frequently — 

 indirect rather than direct. To take a hypothetical case, the 

 hare, with its fur of mingled brown, white, yeUow, and black, is 

 weU protected against its enemies by its coloration, which har- 

 monizes with the colour of the bushes and herbage among which 

 it takes refuge, and renders it less apt to be seen and recognised. 

 Should snow fall, however, the colour of the hare would not only 

 cease to be useful as a means of concealment, but would actually 

 advertise its presence to its enemies, because of its contrast with 

 the surrounding snow. Should, therefore, a severe winter with 

 much snow set in, those hares whose fur had a greater propor- 

 tion of white would be more likely to escape detection by their 

 enemies, such as the fox, the badger, or the wild cat, than those 

 with a darker fur. The white variety would survive, the dark 

 1 The Origin of Species, p. 110. 



