36 FOOT-NOTES TO EVOLUTION. 
stages of incompleteness before the organ is finished. 
Each of these stages finds a more or less perfect repre- 
sentation in the adult condition of some animal of less 
complexity. The long-continued “ survival of the fittest ” 
brings these organs to a greater and greater perfection. 
But by the side of these creatures with the most complex 
organs will be found those in which the development of 
some particular part may be less and less complete. 
An-organ highly developed in one animal may be quite 
rudimentary and imperfect in some other animal whose 
superior fitness may be in some other direction. Thus 
fitness for underground life relieves the mole from the 
need of good eyes. Skill to live by his wits relieves 
man from the need of the monkey’s power to climb 
trees. Somewhere in the animal kingdom we may find 
each degree of each organ’s development. These or- 
gans in their varying degrees of complexity corre- 
spond more or less perfectly to the 
several stages of development of the 
same organ in the individual of the 
highest type. The record of the devel- 
opment of the individual is in a way the recapitulation 
of the past history of its species. “ The physical life of 
the individual is an epitome of the history of the group 
to which it belongs.”” Thus the embryonic life of man 
corresponds, so far as we can trace it, to the history of 
that branch of the group of vertebrates which has cul- 
minated in man. Each individual lives over again the 
life of the race. ‘Under each grave lies a world his- 
tory,” * says a German proverb. This fact is, however, 
no mysterious or meaningless law. It is simply a natural 
result of the processes of heredity. Heredity repeats 
that which has been, and natural selection suppresses 
The individual 
repeats the his- 
tory of the race. 
* “Unter jedem Grab liegt eine Weltgeschichte.” 
