436 



PHYSIOLOGY 



from above downwards. 1>\ stimulation of the precentral convolution we net 

 movements of the leg, arm, and face ; though, as is shown in the diajinmi. 

 within these larger areas smaller areas can be distinguished for definite 

 co-ordinated movements of the different parts of the body. 



Anus & Vagina 



. Sulcus . . 

 .*' .central is 



Abdomen 



Shoulder 

 Elbow * 

 Wrist " 



Finders 

 & thumb 



Ear-"'-'' / / 

 Eyelid /Closure 



Nose of j*" Opening . 



of jaw Vocal 



cords Mastication 



Kic. 22S. 



Sulcus centralis 



Sole. Central. Anu * * ^V*^ 



SulccaUcso 



Sulc.caLcarin. 



FIG. -27, outci Miil.ur; |-'ji.. 2'Js. iniHT surface cf brain of rhimpan/.cr. sli(i\\iiiL r 

 movrmriits ,,l)tained by excitation of the motor areas. (SHERRINOTON.) 



NATURE OF MOVEMENTS EXCITED. The movements obtained by 

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

 ments observed during the normal willed or spontaneous activity of the 

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



