DISTANCE CEPTORS EMOTIONS 121 



modification of the response through experience and 

 heredity; the evidence of histologic changes found 

 in the brain cells after response has been effected, and 

 in the eye which has been exhausted by intense light ; 

 the fact that electric energy is generated in the nerve 

 centers and flows along the nerve paths ; the fact that 

 the response of muscles and glands to an electric cur- 

 rent is the same as their response to a nerve impulse ; 

 and the conclusion of Crehore and Williams, 1 that 

 the propagation of nerve impulses obeys the laws of 

 the propagation of electricity along conductors with 

 distributed capacity. All these points will be consid- 

 ered later. The point which concerns us here is the 

 fact that the response to distance ceptor stimulation 

 is specific to the exciting stimulus, just as are the re- 

 sponses to contact and chemical ceptor stimulation ; 

 and that like the latter they serve a useful purpose 

 in the life of the species. The evidences of this are 

 the gross phenomena, the physiological modifications, 

 and the histological and chemical changes which are 

 produced in the cells of certain organs in the reactions 

 to distance ceptor stimulation, all of which show that 

 in these reactions, whether they are manifested by 

 muscular activity, by inhibition of muscular activity 

 or by emotion, the entire organism is integrated to 

 perform a physical act of muscular exertion, indistin- 

 guishable from the motor acts of self-defense and 

 species preservation. 



Muscular exertion is produced for three principal 



1 Crehore and Williams : Electric current in conductors with 

 distributed capacity considered in relation to the propagation 

 of the nerve impulse. Proceedings of the Society for Experimental 

 Biology and Medicine, 1914, XI, pp. 58-59. 



