THE STORY OF THE BRAIN AND NERVE 123 



THE CEREBRUM. A large amount of investigation 

 and research has resulted in the mapping of the 

 cerebrum into definite regions and centres. The 

 centres of the cerebrum, as revealed by science, are 

 not in any sense to be confused with those which 

 figure in the old phrenological systems of localisation 

 of brain functions. Phrenology is an effete mode of 

 explaining either the brain constitution or the work- 

 ing of the organ. The general distribution of brain 

 centres may easily be remembered if we suppose 

 that each lobe, or half of the cerebrum, is divided 

 into three parts (Fig. 34). Of these, the front third 

 may be regarded as devoted to the higher operations 

 of mind. The cells of the frontal or forehead lobes 

 of the brain are undoubtedly those which may be 

 credited with exercising the highest mental functions 

 -represented by the exercise of our consciousness and 

 will. This section may therefore be termed the 

 intellectual area of the brain. The middle third we 

 may term the motor area, since the centres repre- 

 sented in the arrangement of brain cells in this 

 region are devoted to the government and control of 

 the muscles of the body. The hinder third of each 

 half of the cerebrum may be termed the sensory area. 

 Here we find the centres specially connected with 

 the receiving of impressions from eyes, ears, and 

 other organs of sense, and it is probably in these 

 centres, also, that such messages are fitted for 

 transmission to the intellectual centres, there to 

 have their meaning translated and appreciated by 

 our consciousness. 



THE DOUBLE BRAIN. The two halves of the 

 cerebrum, right and left, govern each the opposite 

 side of the body, although in a limited degree each half 

 also exercises a certain amount of control over its 



