86 FOOT-NOTES TO EVOLUTION. 



being crowded by competing forms, often exist in count- 

 less numbers. 



The distribution of fishes may illustrate this. The 

 most favourable condition for fish life is found about 

 coral reefs, in the clear, equable waters of the tropics. 

 Here many forms find favourable conditions, but the 

 competition among their individuals is severe. In 

 arctic waters but few species appear ; the most are ex- 

 cluded by the temperature itself. But these few forms 

 are represented each by myriads of individuals. Only 

 a few kinds can enter into competition. The struggle is 

 not that of species against species; it is the survival of 

 those that can react from the environment, that can 

 maintain themselves against the hard conditions of life. 

 But these conditions are not hard to these individuals 

 who survive. The arctic life is the life they are fitted 

 for. The struggle for existence is not felt as a stress or 

 strain by the adapted. 



Hence comes the fact noticed by Darwin, that, while 

 all intelligent men admit the struggle for existence, very 

 few realize it. Men in general are fitted to the struggle 

 endured by their ancestors, as they are fitted to the 

 pressure of the air. They do not realize the pressure 

 itself, but only its fluctuations. Hence it comes that 

 many writers have supposed that the struggle for exist- 

 ence belonged only to animals and that man is or should 

 be exempt from it. Competition has been identified with 

 injustice, fraud, or trickery, and it has been supposed 

 that some act of legislation would put an end to it for- 

 ever. But competition is inseparable from life. The 

 struggle for existence may be hidden in social conven- 

 tions, but it can never be extinguished. Nor should it 

 be, for it is the essential force in the progress of life. 



Malthus's law of population, often quoted, is in sub- 

 stance this : Man tends to increase by a geometrical 



