PAST AND FUTURE OF ANIMAL LIFE 139 



these qualities not solely and directly to the possession 

 of good laws, education and hygiene, but partly 

 because they have lived for a long series of genera- 

 tions in an environment of their own creation which 

 has favoured certain types of individual more than 

 others. In short it is man's business to create his 

 environment, but unless heaven sends his offspring 

 more capacity, his labour is lost as far as evolution 

 is concerned. The growing conviction that organic 

 evolution has taken place as the result of a selection 

 of individuals exhibiting variations that have arisen 

 mysteriously or, as we may say, by chance, has given 

 rise to the school of Eugenists, who propose con- 

 sciously to enforce the process of selection, if not for 

 the survival of the fittest, at least for the eradication 

 of the least fit. It is impossible to estimate the 

 influence which this school of thought may exert in 

 the future ; the opinion of mankind may waver or 

 decide as to the relative advantages of contracting 

 marriages for reasons of sentiment or of public utility ; 

 and the enactment of laws precluding lunatics and 

 diseased persons from the privilege of propagating 

 their kind might do more to stop the deterioration 

 than actively to further the progress of the human 

 race. 



2. The earlier ideas of evolution have been 

 modified in another direction, and the dazzling 

 picture of universal progress has been tinged with 



