THE CEREBRUM 2JI 



Functions of the Cerebrum. The superior development 

 of the intellect in man is the most predominant characteristic 

 distinguishing him from the lower animals. That many such 

 animals are possessed of a certain degree of intelligence is 

 not usually denied ; and the nature of their mental oper- 

 tions, though they are insignificant as compared with man's, 

 may be admitted as identical with his. The most striking 

 difference in the nervous system of man as compared with 

 that of inferior animals is the large size of the cerebrum in 

 the former. This is not surprising when it is admitted that 

 in the substance of this part of the encephalon is the seat of 

 those faculties which manifest themselves in mental opera- 

 tions. 



The seat of the changes, if they be changes, which result 

 in mental operations is supposed to be in the frontal lobes; 

 these are insensible and inexcitable, but severe injury to 

 them, as by hemorrhage, is followed by a cessation of mental 

 activity; congenital defects also cause a corresponding de- 

 crease in the mental caliber. 



From what has been said it is evident that the cerebral 

 hemispheres are capable of generating motor impulses and 

 receiving impressions general and special; but predominat- 

 ing in importance over these functions is the fact that the 

 gray substance of the cerebrum is essential to the exercise 

 of the intellect even to the existence of that indefinite some- 

 thing called the mind. 



It is by the cerebrum that we perceive and retain impres- 

 sions, that we understand, imagine, reflect, reason and judge, 

 and thus concoct and issue the mandates of our will. It is 

 the link which connects our impressions and our purposeful 

 actions. 



In animals upon which experiments have been made it is 

 found that life may persist for a time after the removal of 

 the hemispheres, and that, outside of the cessation of men- 

 tal activity, the results are not so marked as one would on 

 first thought suppose. Stupor and absence of the ordinary 



