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 
