102 GRAND STRATEGY OF EVOLUTION 



There is also the union of one life with another in 

 marriage, and in the many other cooperative associa- 

 tions of individuals, that constitute herds, flocks, fami- 

 lies, tribes, and states. 



There is also the fruitful nuclear exchange, or the 

 mingling of the substance of two individuals into one, 

 common among lower plants and animals, called con- 

 jugation. And finally, in sexual reproduction, there 

 is the almost universal method of uniting the male and 

 female germ cells, and their chromosomes, to form a 

 new being, or ovum, whose greatly increased powers of 

 life and growth are doubtless due to some adaptive reor- 

 ganization of its constituent parts. 



We may regard this universal merging of male and 

 female cells in sexual reproduction, and the cooperative 

 association of male and female organisms in the higher 

 phases of life, as an attempt on the part of each to 

 capture and assimilate the other for its own aggran- 

 dizement, or growth. This attempt results, like so 

 many others of like nature, in mutual adaptation and 

 mutual service, or in united action for a larger creative 

 result. 



In all these cases, the individual profits and losses 

 of cooperative living are fairly equally divided, and 

 the methods of living are such that each constituent 

 life becomes largely, or wholly, dependent on the other. 

 The transaction is mutually serviceable and profitable, 

 for each one gives the other, through a great variety 

 of channels, some of its own powers, and the combined 

 lives thereby acquire new capacity for world service 

 which the constituents alone could not possess. It is 

 one of the larger phases of growth. 



9. Unprofitable Mergers. Parasitism. But this is 



