THE NERVOUS SYSTEM 35 



total weight, yet this very small proportion of 

 his body serves him as the material basis for a 

 whole Hf e of intelligent activity and is the part 

 of the nervous system chiefly concerned in 

 yielding that almost impalpable product, hu- 

 man personality. Had Descartes been truly 

 scientific, and had he known in his time the 

 anatomy and physiology of the nervous sys- 

 tem as it is known to-day, he would have de- 

 clared that the cerebral cortex and not the 

 pineal body was the seat of the soul. 



From the foregoing sketch some idea can 

 be gathered of the significance of the nervous 

 system for man as a social organism and of 

 the part it plays in his daily life. From a back- 

 ground of simple reflexes which attend to a 

 long range of his bodily needs, and which 

 are unassociated or only slightly associated 

 with consciousness, rise the superstructures 

 concerned with his higher nervous functions 

 such as memory and voluntary action. These 

 general nervous functions have done more to 

 make an individual of him than any other el- 

 ements in his nature. His circulatory mechan- 

 ism with its centralized heart has added much 

 to this unity, but even such organs are secon- 

 dary to the nervous system. When we reflect 



