V THE MENTAL PHENOMENA OF ANIMALS 131 



foot of the same side ; and, if that foot be held, 

 performs the same operation, at the cost of much 

 effort, with the other foot, it certainly displays a 

 curious instinct. But it is no less true that the 

 whole operation is a reflex operation of the spinal 

 cord, which can be performed quite as well when 

 the brain is destroyed ; and between which and 

 simple reflex actions there is a complete series of 

 gradations. In like manner, when an infant 

 takes the breast, it is impossible to say whether 

 the action should be rather . termed instinctive or 

 reflex. 



What are usually called the instincts of animals 

 are, however, acts of such a nature that, if they 

 were performed by men, they would involve the 

 generation of a series of ideas and of inferences 

 from them ; and it is a curious, apparently an 

 insoluble, problem whether they are, or are not, 

 accompanied by cerebral changes of the same 

 nature as those which give rise to ideas and 

 inferences in ourselves. When a chicken picks up 

 a grain, for example, are there, firstly, certain 

 sensations, accompanied by the feeling of relation 

 between the grain and its own body ; secondly, a 

 desire of the grain ; thirdly, a volition to seize it ? 

 Or, are only the sensational terms of the series 

 actually represented in consciousness ? 



The latter seems the more probable opinion, 

 though it must be admitted that the other alter- 

 native is possible. But, in this case, the series of 



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