2 5 8 



THE EVOLUTION OF SEX. 



A simple organism, which merely feeds and grows, and liberates 

 superfluous portions of its substance to start new existences, is plainly 

 living an egoistic and individualistic life. But whenever we find the 

 occurrence of close association with another form, we find the first 

 rude hints of love. It may still be almost wholly an organic hunger 

 which prompts the union, but it is the beginning of life not wholly 

 individualistic. Hardly distinguishable at the outset, the primitive 

 hunger and love become the starting-points of divergent lines of egois- 

 tic and altruistic emotion and activity. 



Ideal unity, 



society. 



"£ family. 



offspring. 



mates. 



N v R 



Fig. 99. — Protoplasmic Identity. Diagrammatic Representation of the Relations 

 between Nutritive, Self-Maintaining, or Egoistic, and Reproductive, 

 Species-Regarding, or Altruistic Activities. 



The differentiation of separate sexes; the production of offspring 

 which remain associated with the parents; the occurrence of genuine 

 pairing beyond the limits of the sexual period; the establishment of 

 distinct families, with unmistakable affection between parents, offspring, 



