THE HEMISPHERES. 



489 



lateral part of the hemisphere (7, 8, 9), immediately about the supra- 

 Sylvian fissure. 



The action of the cerebral convolutions in producing muscular con- 

 traction, when this contraction is definite and limited, is always a 



Fig. 161. 



Fig. 162. 



BRAIN OF THE DOG. Fig. 161, view from above; Fig. 162, profile view; showing the cen- 

 tres of motion in the cerebral convolutions. F. Frontal fissure. S. Fissure of Sylvius. The 

 unshaded part is that exposed by the opening in the skull, F. Frontal fissure. S. Fissure 

 of Sylvius. 1. Flexion of head on the neck, in the median line. 2. Flexion of head on the 

 neck, with rotation toward the side of the stimulus. 3,4. Flexion and extension of anterior 

 limb. 5, 6. Flexion and extension of posterior limb. 7, 8, 9. Contraction of orbiciilaiia oculi, 

 and the facial muscles in general. 



crossed action ; galvanization of the convolutions, on either side of the 

 brain, exciting movement in the muscles, both of the limbs and face,, 

 on the opposite side of the body.. On the other hand,, galvanization of 

 32 



