SOCIAL EVOLUTION AS A BIOLOGICAL PROCESS 257 



Hydra only in the degree of differentiation exhibited by 

 its constituent elements. Instead of a loose network 

 of nerve-cells there is the far more complex nervous 

 system whose evolution has been outlined in the sixth 

 chapter. The blood-vascular and respiratory and ex- 

 cretory systems have become well organized, in response, 

 so to speak, to the demands on the part of the nervous 

 and alimentary organs that they may be relieved of the 

 tasks of circulation and respiration and the discharge 

 of ash-wastes. Therefore the cells which make up an 

 insect and a man are more diverse, they have more 

 varied interrelationships, and they are far more inter- 

 dependent then in the case of the components of Hydra. 

 Yet all the many-celled organisms that we are so accus- 

 tomed to regard as individuals are really communities, 

 demonstrating the existence and partial antithesis of 

 the great laws of egoism and altruism, which are trace- 

 able even down to Amoeba and its like. 



So much has been made of the lower kinds of cell- 

 associations because the mind of the layman is uncon- 

 sciously imbued with the idea that human society is a 

 new thing, an idea which we now see it is necessary 

 to discard at the outset. Indeed, the cell-association 

 of the Hydra and insect type is a more compact and a 

 more stable kind of community than any group of 

 human individuals worked out by nature toward the 

 present end of the whole scheme of evolution. That 

 is to say, the subordination of cell-interest to cell-group 

 welfare, while it must not go so far as to render the unit 

 incapable of doing its work, is sufficiently advanced to 

 make uncontrolled individualism impossible. Let any 

 class of Hydra's cells, such as the nerve or muscle net- 



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