1040 



CORTICAL MOTOR REGION. 



[BOOK in. 



sulcus (Fig. 126), is the "area for the head," that is to say for 

 movements of the head brought about by contractions of the 

 muscles of the neck. 



Ventral to this again, in front of the precentral sulcus is the 

 " area for the eyes," that is to say, for contractions of the ocular 

 muscles ; and behind the precentral sulcus, ventral to the arm area, 

 lies a small area for movements of the eyelids, brought about by 



FIG. 125. OUTLINE OF BRAIN OP MONKEY (MACACUS) TO SHEW PRINCIPAL SULCI 

 (FISSURES) AND GYRI (CONVOLUTIONS). (Natural size.) (Sherrington after 

 Horsley and Schafer.) 



The brain figured is the same as that in Fig. 126, and the two figures should be 

 consulted together. Over each sulcus, purposely printed very thick, the name is 

 written in small capitals, over each gyrus in italics, x indicates the small depres- 

 sion, hardly to be called a sulcus, which is supposed to be homologous with 

 the superior frontal sulcus of man; and w, y, z similarly indicate sulci whose 

 homologies are not certain. For some synonyms see Figs. 129, 130. 



contractions of the orbicularis muscle. Ventral to this again is 

 the 'area for the face,' in which we may distinguish an area for 

 the mouth, that is an area stimulation of which produces changes 

 in the buccal orifice, opening, shutting, drawing to one side &c., 

 and an area for movements of the tongue. These two areas 



