INTERRELATION OF THE CHEMICAL SENSES 177 



ing pressure, and in a corresponding way the sensations 

 in hearing are much more diverse than those in touch. 

 But it is still reasonable to regard hearing as one sense, 

 for its various stimuli grade into one another as its sen- 

 sations do. With taste on the other hand such is not the 

 case. The acid stimulus as an external agent is entirely 

 distinct from the stimuli for the other tastes and the 

 sour sensation as an internal state does not grade into 

 other gustatory sensations. This separateness in stim- 

 uli and in sensations is characteristic of the four kinds 

 of tastes and justifies their acceptance as separate senses, 

 a division that is not permissible in hearing. To con- 

 stitute a single sense implies a reasonable similarity in 

 stimulus, receptive mechanism, and sensation. 



But, as previously pointed out, the initiation of sen- 

 sations is a function of only a limited number of the 

 human receptors. Many of these organs are concerned 

 with activities entirely unassociated with sensation; 

 hence to speak of them as representing a sense seems 

 somewhat inconsistent. If the term receptor is an im- 

 provement over that of sense organ because of its free- 

 dom from implications concerning sensation, it might be 

 well for the same reason to substitute some other term 

 for sense, such, for instance, as recept.^ In that case a 

 recept is that aggregate of action that occurs where the 

 receptive arm of any reflex arc goes into normal activity 

 irrespective of whether this activity is productive of a 

 sensation or not. The recept then includes all the oper- 



^ I am fully aware that this term has already been appropriated by 

 the psychologists for a very different purpose, but as they have taken 

 almost all the terms in the language for their own use, I do not hesitate 

 to reappropriate this one to fill the present need. 



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