CHAPTER V 



ADAPTATION BY MEANS OF DISTANCE CEPTORS 

 EMOTIONS MENTAL STATES 



ADAPTATION to environment in some species of ani- 

 mals, such as the oyster, is secured mainly by reactions 

 to stimulation of the contact and chemical ceptors only ; 

 but in most animals there has been evolved a third 

 method of adaptation to environment by which they 

 are directed toward beneficial objects in their distant 

 environment and away from those that are harmful, 

 thus securing a quicker and surer adjustment than 

 would be possible through contact and chemical cep- 

 tors only. 



The essential difference between the reactions ini- 

 tiated by stimulation of the distance ceptors and those 

 initiated by stimulation of the contact ceptors lies in 

 the fact that in the response to distance ceptor stimu- 

 lation the animal as a whole responds, while in the 

 response to contact ceptor stimulation, usually only 

 a portion of the organism is concerned ; consequently 

 the transformation of potential into kinetic energy 

 for the consummation of the response to distance cep- 

 tor stimulation is much greater than in the response to 

 contact ceptor stimulation. Stimulation of the dis- 

 tance ceptors initiates the long series of motor acts 

 connected with the search and fight for food and mates ; 

 the grappling with enemies or fleeing from them. It 



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