158 S. J. HOLMES 



A new point of view in regard to our problem has been presented 

 by Hobhouse in his Mind in Evolution. To illustrate this view 

 let us recur to our chick. When a nasty caterpillar is seen for 

 the first time the visual stimulus sets up a pecking reaction. This 

 is followed by the stimulus of a bad taste which sets up various 

 rejection movements, such as ejection of the food and wiping the 

 bill. The order of events is 



stimulus. . . .pecking. . . .bad taste. . . .rejection. 



When the same kind of caterpillar is met with a second time the 

 stimulus tends to elicit the rejection movements with which it 

 has been associated instead of the movements of pecking. Is 

 not the inhibition due to the fact that the stimulus has become 

 associated with a response which is incongruous with the first? 

 Movements of rejection and avoidance are incompatible with 

 those of pecking and swallowing and it may therefore be unneces- 

 sary to look to any peculiarity of the physiological correlates of 

 pain for an explanation of the inhibition of the original reaction. 

 The stimulus becomes coupled with a new reflex arc; nervous 

 energy is drained off in a new channel, and the future behavior 

 becomes changed. If the taste is a very bad one, a great deal of 

 energy is involved and the connection with the rejection response 

 made very permeable and the rejection movement easily set up. 

 If a person is confronted with a sight of some nauseating medicine 

 he has recently taken, avoiding or rejection movements are set 

 up, such as making a face or even retching movements of the 

 stomach. Is it not these movements or attempts at movements 

 that really inhibit the taking the medicine? This is evidenced by 

 the chick described by Lloyd Morgan, which after an experience 

 with a nast> caterpillar approached one a second time but stopped 

 and wiped its bill and went away as if it actually repeated its 

 first experience. Of course inhibition of the original response 

 does not always involve contrary movements but there may be 

 impulses to such movements which do not issue in action. The 

 principal feature in the modification of action through painful 

 experiences is the assimilation of impulses incongruous with the 

 original one. 



