172 Instinct and Intelligence 



tures which form his cerebral cortex; and that 

 the effective working of his brain, like that of 

 other organs of his body, depends on the struc- 

 tural arrangement of the elements which form 

 its underlying basic substance; while any im- 

 provement of its functions implies a similar 

 improvement in the structures which minister to 

 their performance. Sensations derived from 

 the outer world or else from internal sources 

 form the material from which intellectual pro- 

 cesses are derived ; as Aristotle long ago stated, 

 " Nihil in intellectu quod non fuerit prius in 

 sensu " ; we know, and learn from what we see, 

 feel, hear, taste, and smell. 1 



We may now pass on to consider the evidence 

 on which we base the opinion that, in addition 

 to the above stated functions, specialised areas 

 of the neopallium control the movements of 

 animals so as speedily to adapt them to their 

 environment. 2 



Nervous action is reflex; that is, it depends 

 on the effect produced by energy applied to a 



1 See The Nineteenth Century and After, "A Physiological Basis 

 of Education," by N. C. Macnamara. 



2 A "Lecture on the Investigation of the Higher Nervous 

 Functions," by Prof. T. Pawlow, Brit. Med. Journ., p. 973, 

 October, 1913. 



