Reason and Instinct. 



6523 



of form and structure at a much earlier period than do the cerebral 

 hemispheres. In other words, in our early infancy those portions of 

 our brain through which our higher intellectual faculties are destined 

 to work eventually are just as unfit for their future work as is that 

 portion which is to enable us, — and much earlier, — to walk, to run, to 

 leap, to perform all those complicated and countless movements of 

 limb or member, or portion of member, on which our comfort and well- 

 being so much depend. No wonder, then, that the first actions of the 

 infant are scarcely more than consensual, and the next in order merely 

 Instinctive ; and that the dawning of Intelligence should be slow and 

 faint and indecisive ; or that its growth and increase, when distinctly 

 produced, should be but gradual and halting, and so much under the 

 influence of the Emotional and Instinctive faculties. But more than 

 a mere passing notice must be given to the results of proper training 

 and favourable circumstances, as assisting in the development of the 

 brain. The cerebral hemispheres of inferior races of mankind, among 

 whom neglect of mental culture and habits approaching those of brutes 

 are found to prevail — influences certainly unfavourable to Intellectual 

 development, and, as it would appear from what follows, to physical 

 development of the organs of Intellect also — present a symmetrical 

 disposition of the convolutions similar to that in the case of the 

 newly born infant, or of the brute animal. 



However inexplicable the nature of the connection between mind 

 and nervous matter, it is yet " impossible to explain," says an able 

 physiological writer, " the great superiority of the human brain, both 

 in organization and absolute quantity of nervous matter which it con- 

 tains, without admitting its connection with the mind, and the influence 

 exerted upon its nutrition and growth by that immaterial principle. 

 We have many proofs to show that the neglect of mental cultivation 

 may lead to an impaired state of cerebral nutrition. It may readily 

 be understood that mental and physical development should go hand- 

 in-hand together, and mutually assist each other." " In fact," writes 

 Tiedemann, " the cerebral convolutions become atrophied, either from 

 continued absence from all cerebral excitement, as well as from any 

 other cause of intellectual weakness." 



And what is especially worthy of notice in this connection is, that 

 any such change as may by these means be wrought upon the con- 

 figuration or dimensions of the cerebrum, may, under certain circum- 

 stances, become — so to speak — stereotyped. Indeed this result is 

 implied in what has been already stated with reference to the symme- 

 trical cerebral hemispheres peculiar to peoples of a low or degraded 



