244 



PHYSIOLOGY. 



body, it also, in part, has control of its own side. Paralysis 

 of one side (hemiplegia) is due to injury of the opposite 

 cerebral hemisphere. 



Location of Brain Functions. Much has been learned 

 of late years as to the location of special functions in the 

 brain. Many of the motor centers have been determined 



CENTRAL FISSURE 



MOTOR AREA X 



FISSURE OF SILVIUS 



Fig. 82. Location of Brain Functions. 



in the following manner : In some of the lower animals 

 the brain has been exposed, and on stimulating certain 

 portions with an electric current the movements that fol- 

 lowed were noted. In monkeys, " particular movements 

 of the arm, forearm, hand, and thumb can be produced by 

 excitation of particular spots, almost as regularly as definite 

 notes can be sounded on a piano by touching particular 



