192 



VETERINARY PHYSIOLOGY 



itself the function, is capable of education, just as the lower 

 spinal centres seem capable of adaptation. 



(b) Stimulation by electricity causes movements of group 

 of muscles of the opposite side of the body and of muscles 

 on both sides when bilateral co-operation is required. 



These movements are elicited by much weaker currents 

 than are required to produce them on stimulating the typical 

 receiving area already studied. 



If the cortex is stripped off and the white fibres below 



Awair^gl^- 





Abcfofnen 



Pheat 



pn§er3 

 (5 thumbs./ 



^"^ of J^'"- Opting ; "^ 



Fig. 95. — Left Hemisphere of Brain of Chimpanzee to show the results of 

 stimulating different parts. The Sulcus Centralis is the fissure of 

 Rolando. (From Grunbaum and Sherrington.) 



it are directly stimulated, the latent period is shortened and 

 the strength of current required to produce movements is 

 greater. 



The work of Grunbaum and Sherrington on the brain 

 of anthropoid apes has shown that the discharging mechanism 

 is chiefly in the pre-central convolution (fig. 95), extend- 

 ing forwards into the posterior parts of the superior, middle 

 and inferior frontal convolutions, with a patch far out in the 

 frontal area by stimulation of which movements of the eyes 

 are produced. This is present only in men and apes which 

 use binocular vision. It is associated by a band of 



