36 BIOLOGY AND SOCIAL PROBLEMS 



that many of the lower animals, like the sea 

 anemones, for instance, have only the merest 

 rudiments of a nervous system, and that this 

 system is there concerned simply in calling 

 muscles into action and exhibits practically 

 no central functions, we begin to appreciate 

 how strikingly different the conditions are in 

 higher and lower forms. Each tentacle of a 

 sea anemone contains its own neuro-muscular 

 mechanism and will continue to respond to 

 food particles after it has been severed from 

 the body. Its action is as independent of the 

 rest of the animal as the vertebrate heart is of 

 the body in which it grew. But the sea anem- 

 one, instead of possessing only a few such 

 organs as the vertebrate does, is constructed 

 almost entirely upon this plan. Its nervous 

 functions are most diffuse and subordinate ; 

 its chief activities are feeding and reproduc- 

 tion. If man can be described as an organism 

 whose tour-de-force is intellectual, the sea 

 anemone is one whose culminating activities are 

 assimilation and growth. This condition of 

 affairs is characteristic of most of the lower an- 

 imals and represents unquestionably a primitive 

 stage before which the nervous system could 

 scarcely be said to have existed. In the higher 



