CEREBRAL LOCALIZATION OF FUNCTION. 



211 



For diagnostic purposes the motor areas for the face and limbs 

 have been subdivided as follows : 

 i. The face area may be divided into an upper part, comprising about 



one third, and a lower part, comprising the remaining two thirds. 



FIG. 27. DIAGRAM OF THE MOTOR AREAS ON THE OUTER SURFACE OF A 

 MONKEY'S BRAIN. (Horsley and Schafer.) 



FIG. 28. DIAGRAM OF THE MOTOR AREAS ON THE MARGINAL CONVOLUTION OF A 

 MONKEY'S BRAIN. (Horsley and Schafer.) 



In the upper part are centers governing the movements of the 

 muscles of the opposite angle of the mouth and of the lower face. 

 The anterior portion of the lower two thirds controls the move- 

 ments of the vocal cords, and may be regarded as a laryngeal cen- 



