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 is a 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. 



