84 FOOT-NOTES TO EVOLUTION. 
“not indiscriminate, but it will first and mainly com- 
prise those individuals least able to resist attack.” 
This is the essential fact upon which rests Herbert 
Spencer’s law of “the survival of the fittest.” At the 
same time the survival of the fittest does not tell the 
whole story of natural selection. But a small part of 
the actual characters of animals and plants can be 
traced directly and solely to the principle of utility. 
The survival of the existing likewise is a large element 
in the ‘great process of natural selection. Thus, a water 
bird has webbed feet. The webbing is useful in swim- 
ming. Its presence is due to its-utility. The survival 
of the fittest in water birds may mean the survival of 
the best swimmer, and the best swimmer is the one with 
the most useful webbing. But a character quite as per- 
sistent may be a perfectly useless one, as a special ar- 
rangement of the plates on the tarsus, or the flattening 
of a single claw. This may have in itself no utility at 
all. Its presence may not be due to the survival of the 
fittest. It persists because such a character was pos- 
sessed by some ancestor. It has been retained through 
heredity. The nails must have some form, the plates 
some arrangement, the wing coverts some colour. This 
ancestral form or colour is as good as some other would 
be. Hence comes its persistence, which is simply a szr- 
vival of the existing, no question of relative fitness being 
involved. 
From the “survival of the existing” arises the per- 
sistence of those forms which actually inhabit a given 
district whether they be ideally the fittest or not. By 
such means the faune of isolated regions are perpetu- 
ated, the barriers of land or sea or climate excluding 
them from competition with the “ fitter’ organisms that 
may inhabit other regions. “ Possession is nine points 
of the law” of organic survival, as it is said to be else- 
