THE EVOLUTION OF SEX 49 



characters; and this was the great step of 

 sex-dimorphism. It need hardly be said that 

 in this we find every conceivable grade of 

 contrast. 



Besides the divergence in structure, there 

 is a functional contrast between male and 

 female. In face of the extraordinary variety 

 of the Animal Kingdom, generalisation has 

 its hazards; but, on the whole, we may say 

 that the male tends to more intense metabol- 

 ism, to more exuberant expenditure of energy, 

 to live a keener but shorter life, to have much 

 less expensive reproduction, to be more im- 

 petuous, combative, and experimental, and 

 to be the more divergent from the youthful 

 and the ancestral type. Yet the female is 

 not, therefore, necessarily the less evolved, 

 since her relative nearness to the ancestral 

 stock, her less accented specialisation, her 

 persistent youthfulness may also carry with 

 it the very promise of the race. Hence in 

 fact the divergent types of masculine and of 

 feminine beauty in our own species, the 

 former more strongly individualised, but the 

 latter by common consent more humanised, 

 and thus more adapted to the expression of 

 the ideals of racial and of social evolution. 

 Biology and art, mythology and poetry are 

 thus not the separate cultures we conven- 

 tionally regard them, but correlated aspects 

 of the ascent of life. 



SEX- AWARENESS. Another step in the 

 evolutionary ladder is represented by those 

 animals which show sex-awareness, which 

 give distinct evidence that the presence or 

 proximity of one sex acts as a stimulus to 

 D 



