CHAP, ii.] 



THE BRAIK 



745 



than is the corresponding area in the dog. Its outline (Fig. 

 123) is roughly that of a truncated triangle bisected by the 

 central fissure, with the broad base at some distance from the 

 mesial line, and the truncated apex reaching on the lateral sur- 

 face of the hemisphere to a well-marked bend in the lower part 



TRUNK"-.. 



FIG. 123. LEFT HEMISPHERE OF THE CEREBRUM OF MACACUS MONKEY VIEWED 

 FROM ITS LEFT SIDE, AND FROM ABOVE. (Natural size.) (Sherrington 

 after Horsley and Beevor.) 



The figure shews the positions of the portions of the cortex concerned with 

 movement of various parts, and with the senses of sight, smell, and hearing. The 

 cortical area connected with the movements of the leg is shaded vertically across, 

 that with the movements of the arm horizontally, and that with the movements 

 of the trunk in a slanting direction ; the area connected with movements of 

 the head (neck), face, and eyes is dotted. The course of the chief fissures is 

 indicated by single lines. 



of the central fissure. Behind, it reaches as far as the intra- 

 parietal fissure which somewhat sharply defines its hind border, 

 and in front it ceases no less definitely at some little distance 

 behind the precentral fissure. Further examination shews that 

 the whole area is divided into areas corresponding to movements 



