THE NERVOUS SYSTEM 37 



forms, however, this system has far outstripped 

 the others in its growth, till in the mammals 

 and especially in man it has reached a position 

 of supreme dignity. Thus the nervous system, 

 though it originated later than some other sets 

 of organs, has in the higher forms attained to 

 paramount importance. 



With the evolution of the nervous system 

 and the differentiation of the cerebral cortex 

 came the possibilities of that form of compli- 

 cated intellectual life that we know in our- 

 selves. Though less than a cubic inch of our 

 substance is really devoted to this form of ac- 

 tivity, it is as precious a cubic inch as any we 

 possess. By means of it we cherish the tradi- 

 tions of the past; its activities include all our 

 conscious states, our simple sensations, desires, 

 hopes, and aspirations, our sense of shame and 

 regret at deeds of unworthiness, our joy in 

 generous acts, our knowledge of all these 

 things; from it emanate the impulses to 

 those steps which mark us as dishonest or hon- 

 est, extravagant or thrifty, secretive and de- 

 ceptive or frank, open, and free, cold or affec- 

 tionate, in short all those signs which stand 

 for personality. Socially no part of our body 

 is more precious than this cubic inch of cortex. 



