CHAP. XXVI.] VOLUNTARY MOVEMENTS. 573 



destruction of other regions of the surface of the brain in 

 Monkeys, were followed by no such excitations or abolitions 

 of Movements. 



Details cannot here be given as to the effects produced 

 by localized irritations or destructions of limited parts of 

 the Convolutions within this ' excitable area.' For these 

 the reader is referred to Chap. viii. of Ferrier's work. 

 The principal conclusions at which he has arrived may, 

 however, be gathered from a careful study of Figs. 182, 183, 



FIG. 182. Lateral aspect of Monkey's Brain, showing the relative positions of the 

 so-called ' Motor Centres ' in the left Cerebral Hemisphere. (Ferrier.) For rei'erences 

 see Text, and also Fig. 172. 



in which, as a result of his investigations, the seats of the 

 different supposed ' centres ' for special Movements are 

 indicated. They are as follows : 



(1.) Centres for movements of the opposite leg and foot, such as 

 are concerned in locomotion in postero-parietal lobule. 



(2, 3, 4.) Centres for various complex movements of the arms 

 and legs, such as are concerned in climbing, swimming, &c. in 

 the convolutions bounding the upper extremity of the fissure of 

 Rolando. 



(5.) Centres for the extension forwards of the arm and hand, as 

 in putting forth the hand to touch something in front in posterior 

 extremity of superior frontal convolution. 



