90 PHYSICAL EXPEESSION. 



superior frontal convolution, at its junction with 

 the ascending frontal, is the centre for the extension 

 forwards of the arm and hand, as in putting forth 

 the hand to touch something in front. 



"(6), situated on the ascending frontal, just be- 

 hind the upper end of the posterior extremity of 

 the middle frontal convolution, is the centre for 

 the movements of the hand and forearm in which 

 the biceps is particularly engaged, viz. supination 

 of the hand and flexion of the forearm. 



" (7) and (8), centres for the elevators and depres- 

 sors of the angle of the mouth respectively. 



" (9) and (10), included together in one, mark the 

 centre for the movements of the lips and tongue, 

 as in articulation. This is the region, disease of 

 which causes aphasia, and is generally known as 

 Broca's convolution. 



" (11), the centre of the platysma, retraction of 

 the angle of mouth. 



" (12), a centre for lateral movements of the head 

 and eyes, with elevation of the eyelids and dilata- 

 tion of the pupil. 



"(a), (&), (c), and (d\ placed on the ascending 

 parietal convolution, indicate the centres of move- 

 ment of the hand and wrist. 



" Circles (13) and (13'), placed on the supra-mar- 

 ginal lobule and angular gyrus, indicate the centre 

 of vision. 



"Circles (14), placed on the superior tempero- 

 sphenoidal convolution, indicate the situation of 

 the centre of hearing." 



When we consider that any expression by move- 



