Mentality and Self-Consciousness 79 



themselves are polar structures, the surrounding 

 electric field will also be polarized, and any polari- 

 zation of the electric fields around the openings at 

 the ends of the polygonal compartments will re- 

 sult in selective and unequal diffusion of the ions 

 therethrough. A similar selective and unequal 

 diffusion may also take place through the inter- 

 stices in the sides of the terminal fibrils. As long 

 as conditions are in equilibrium, a certain differ- 

 ence of potential will be established and nothing 

 further will happen; but upon disturbing or irri- 

 tating the fibrils, as by applying pressure, heat, 

 or electricity, the dimensions or electrical condi- 

 tions of these interstices may change, and conse- 

 quently also the relative rates of diffusion of posi- 

 tive and negative ions therethrough which will 

 produce the electric impulses to be propagated 

 along the nerve-fibers. 



When a sensory impulse is produced the energy 

 is not always transmitted only to the motor nerves 

 but a portion of it may pass through the spinal 

 cord or through the cranial nerves to the brain 

 and finally to the supra-granular or molecular 

 layer of the cerebral cortex which is generally 

 thought to be the seat of self-consciousness. It 

 does not seem likely that sense-perceptions of 

 short duration can cause the formation in the 

 cerebral cortex of new fibrils because some sense- 



