138 HEREDITY AND SOCIETY 



qualities are beneficial and have a survival value. Each 

 type that migrates will, in time, either die out or ex- 

 hibit the inborn characters which fit it for residence in 

 its new place of abode. The original prehistoric migra- 

 tory movements over the surface of the earth were 

 extremely slow, and the type had time to alter and evolve 

 new combinations of characters during its journeyings. 

 But with our rapid means of transport and, in England, 

 with the unrestricted right of entry to our shores, any 

 alteration of environment by legislative action or social 

 endeavour leads to an immediate movement of popula- 

 tion. We make the conditions of life easier. Does a 

 good class of citizen take advantage of the betterment 

 to spread itself out, or do poorer specimens of humanity 

 crowd in and seize upon the opportunity to multiply 

 up to their lower level of subsistence ? We stiffen the 

 standard required for successful survival. Do we 

 squeeze out some deserving members of the com- 

 munity, or do we discover and set free the families in 

 which energy and endurance lie concealed ? 



It is a fundamental mistake to think that any type 

 can dwell anywhere. The migrant himself may not 

 perish prematurely, but the permanent survival of the 

 stock he represents depends on the power of adjusting 

 the environment and the possibilities of adaptation 

 inherent in the individual. Tall men will survive in 

 one set of circumstances, short men are essential to 

 another ; there is a relation to be observed between 

 the intensity of light of a region and the depth of 

 pigmentation of the skin ; nostrils are narrow in cold 

 climates and broad in damp, warm atmospheric condi- 

 tions. The size of the brain and the general level of 



