NERVE 



183 



-K' 



:;:^ 



^ 'M 



l: i 



/ .V^ 



l''^- 



l- ''?i-^i 



a condition of rest, and to the unpleasant 

 state associated with restlessness and crying. 



Only when sensations become more 

 completely integrated in the developing 

 cortex is any real mental life possible. 

 The power of integrating largely de- 

 pends upon : — 



(1) The previous history of the hrain 

 both phylogenetic and ontogenetic. For, 

 just as in the spinal cord channels of 

 action are formed, so in the cerebrum, 

 if a given reaction once follows a given 

 stimulus, it will tend to follow it again. 



3 and 4 



-^^•I 



i 



A B 



Fig. 92. — A, Section of cerebra cortex in the pre-central lobe (a motor 

 area). (For description of zones, see text.) B, Section through 

 cerebral cortex in the region of the calcarine fissure (visual area), 

 stained to show the arrangement of the fibres. (For description of 

 zones, see text.) (Campbell.) 



