THE HIGHER SOCIAL LEVELS 149 



evidence that many of the beneficial effects of 

 relatively unorganized aggregations of animals 

 are the expression of a vague, unconscious mutual 

 co-operation and that the principle of co-operation 

 should rank as one of the major biological principles 

 comparable with the better recognized Darwinian 

 principle of the struggle for existence. 



Let us trace briefly some of the steps in the 

 development of group co-operation from its incip- 

 ient stages such as were suggested in the earlier 

 chapters to the conditions found in closely knit 

 social organizations. In doing so, we shall of 

 necessity see much of the development of the 

 principle of leadership in animal societies. Such 

 a development invites comparison with the evo- 

 lution of co-ordination and of leadership in indi- 

 vidual animals at different levels of their organ- 

 ization. 



The generalized ecological animal communities 

 have a more or less loose organization that is not 

 definitely pointed in any direction. In such 

 communities the process of "muddling through" 

 is the only one that seems to apply. There is 

 interaction between the different biotic elements 

 in the community with each other and with the 

 physical environment, with now the biota and 

 now the physical elements in the ascendency. 

 Such blind interactions are well illustrated in the 



