266 THE ORIGIN OF THE NERVOUS SYSTEM 



of developmental physiology in a new light, and I have 

 ventured to suggest that even the more complex aspects 

 of nervous development and integration are related to 

 the fundamental physiological features of organismic 

 pattern, the gradients. 



From this point the attempt might be made to push 

 suggestion and speculation along these lines into the 

 field of psychology, but we are concerned primarily 

 with the origin of the nervous system rather than with 

 its relations to psychological phenomena. It seems 

 allowable, however, to point out the possibility that 

 the field or content of consciousness at any given 

 moment may be associated with the determination of a 

 field or area of relatively intense physiological activity 

 in a particular region of the cortex as the resultant of 

 the incoming impulses at that moment. If this activity 

 is sufficiently intense, this area becomes for the time 

 being the dominant region and its connections with 

 other parts, together with the physiological conditions 

 in other parts, determine the course of action. Hesita- 

 tion, deliberation, delays, so characteristic of cortical 

 reaction and consciousness, represent the period before 

 complete dominance is attained and can be interpreted 

 in terms of physiological factors. I do not mean to 

 imply that each particular content of consciousness is 

 localized in a particular cortical area, but merely that 

 increased activity in a particular cortical region or 

 regions is itself a resultant of a particular functional 

 complex in the nervous system and the body as a whole, 

 and that if such activity becomes sufficiently intense it 

 determines a certain reaction complex. The structure 

 of the cortex indicates that a general physiological 



