The Theory of Natural Selection. 265 
who happen better to subserve the interests of the 
species. For example, in all organisms a greater or 
less amount of vigour is wasted, so far as individual 
interests are concerned, in the formation and the 
nourishment of progeny. In the great majority of 
plants and animals an enormous amount of physio- 
logical energy is thus expended. Look at the roe or 
the milt of a herring, for instance, and see what a 
huge drain has been made upon the individual for the 
sake of its species. Again, all unselfish instincts have 
been developed for the sake of the species, and usually 
against the interests of the individual. An ant which 
will allow her head to be slowly drawn from her body 
rather than relinquish her hold upon a pupa, is clearly 
acting in response to an instinct which has been de- 
veloped for the benefit of the hive, though fatal to the 
individual. And, in a lesser degree, the parental 
instincts, wherever they occur, are more or less de- 
trimental to the interests of the individual, though 
correspondingly essential to those of the race. 
These illustrations will serve to show that natural 
selection always works primarily for the life-interests 
of the species—and, indeed, only works for those of 
the individual at all in so far as the latter happen to 
coincide with the former. Or, otherwise stated, the 
object of natural selection is always that of producing 
and maintaining specific types in the highest degree 
of efficiency, no matter what may become of the con- 
stituent individuals. Which isa striking republication 
by Science of a general truth previously stated by 
Poetry :— 
So careful of the type she seems, 
So careless of the single life. 
