1 5 o GRAND STRATEGY OF EVOLUTION 



gifts and the common usage of each other's powers 

 depends the existence and unity of the great social life 

 of nature. Its continuity is wholly dependent on the 

 ultimate fruition of this individual self -constructive- 

 ness and self-surrender to this larger purpose. 



3. The Post-sexual Period of Parental Life as an 

 Agency in Social Inheritance. In animal society, par- 

 ents are of little value after the reproductive period, 

 except as food for life at large. The prolongation 

 of life after it has reproduced itself is to be regarded 

 primarily either as a necessary margin of safety which, 

 for economic reasons, must be, cut down to the narrow- 

 est margin, or as a vital surplus for which no profitable 

 investment for saving, or enlarging, racial life is for 

 the time being available. 



There are many cases, familiar to the biologist, 

 where, for a relatively long preliminary period, the 

 parents are elaborately equipped for voracious feeding, 

 and wholly devoted to the rapid accumulation of an 

 organic surplus. Then all this equipment rapidly 

 changes and they become wholly devoted to reproduc- 

 tion and the surrender of their surplus to a new genera- 

 tion. 



But when this second purpose is accomplished, the 

 specialized machinery of sex, such as wings, legs, copu- 

 latory organs, glands, sense organs, and nervous sys- 

 tem, which have so well served to discover each sex 

 to the other, and to bring them and their respective 

 germ-cells into cooperative action, is disorganized and 

 lost in death, it may be with the sexual act, or shortly 

 after that act is consummated. 



In many invertebrates, in mammals, and in prim- 

 itive man, the older members of the social group, or 



