IRRITABILITY 35 



billiard ball is immediate while that of 

 the man may appear to be delayed. The 

 delay is, however, in appearance only. 

 The blow causes immediate changes not 

 evident to the eye: as the result of these 

 we may get a striking visible phenomenon 

 which we call the response. In reality 

 there has been no delay in the response 

 if we include under this term the entire 

 series of reactions which result from the 

 blow. 



In the second place the billiard ball 

 manifests only as much energy as the 

 blow itself imparts while the organism 

 may show in its response very much 

 more. This is because the organism, like 

 a powder magazine, has a considerable 

 amount of stored energy, which can be 

 released by the application of only a 

 little. The tiny spark may have a very 

 small amount of energy as compared to 

 that which it sets free when it falls into 

 the magazine. We see therefore that 

 inequality of stimulus and response is in 

 no way peculiar to living beings. 



