FUNCTIONS OF THE CEREBRAL HEMISPHERES 437 



within these larger areas smaller areas can be distinguished for definite 

 co-ordinated movements of the different parts of the body 



NATURE OF MOVEMENTS EXCITED. The movements obtained by 

 excitation of these areas resemble in every respect the co-ordinated move- 



.FiG. 227. 



Anus & Vagina 



Toes .-' Sulcus 



Abdomen 



Finders 

 & thumb 



ar<">' / / 

 Eyelid .-"'Closure , 



Nose fj* w Opening \ 



of jaw Vocal \ 



cords Mastication 



Sulcus centra/is 



SulccaUoso 



FIG. 228. 

 Sulc. Central. *""&* Vagina. 



\ / Sule.fncencr.maw 



Sulc.porieo 

 'occi*. 



Sulc.calcarin. 



C.S.S. rfe/. 



FIG. 227, outer surface ; FIG. 228, inner surface of brain of chimpanzee, showing 

 movements obtained by excitation of the motor areas. (SHERRINGTON.) 



ments observed during the normal willed or spontaneous activity of the 

 animal. Like the movements evoked by stimulation of a sensory surface 

 they involve therefore the reciprocal innervation of antagonistic muscles. 

 Never do we find simultaneous contractions of antagonists, even where two 



