76 SOCIAL HEREDITY AND SOCIAL EVOLUTION 



readily sacrificed to the good of the race. This is 

 most noticeable among lower organisms, but evident 

 enough among the higher. Among low animals the 

 individual is commonly sacrificed completely in the jj 



reproductive act. The simplest form of reproduction 

 is simple division, in which case the parent always 

 disappears as the offspring appears {Protozoa). 

 In some higher groups (Hydroids) the individual 

 from the beginning of life feeds and grows rapidly, 

 increasing in size and vigor. But this is only in prep- 

 aration for the reproductive act which is its cul- 

 mination. In the act of producing reproductive 

 bodies the energies are all spent, and after this act is 

 performed the individual dies. As we rise in the 

 scale of nature this sacrifice to the reproductive act 

 becomes less universal, and an individual may con- 

 tinue to live for a period representing several sea- 

 sons of reproduction. It is to these higher forms 

 that our attention has been chiefly directed in the 

 study of the laws of evolution. It is the individual 

 and his struggles for his own life that has engaged 

 our attention, until we have failed to appreciate that 

 he is an incident and not the end. Even among 

 higher forms it is clear enough that the apparent 

 purpose of nature culminates in reproduction. The 

 instincts connected with the reproductive act are so 

 strong as to obscure even the ordinary instincts of 

 self-preservation. At the breeding season the 

 salmon is forced by an irrestrainable reproductive 

 instinct to ascend the river to deposit its eggs. This 

 act is doubtless useful for the perpetuation of the 

 species, but it is extremely destructive to the life and 

 interests of the individuals. They ascend the river 

 fat and vigorous and in great numbers. But the 



