190 



VETERINAKY PHYSIOLOGY 



previous stimulation, so that the resulting action may be 

 appropriate to the surroundings, must now be studied. 



Ample evidence is forthcoming that in men and apes the 

 part of the cortex round about and chiefly in front of the 

 central fissure performs this function. In the dog, cat 

 and pig it is situated round the cruciate fissure (figs. 52, 

 p. 115, and 94). 



Tig. 94. — {a) Surface of the left Cerebral Hemisphere of a Monkey to shoM' 

 the situations of some of the Discharging Mechanisms (front to left) ; 

 {h) Mesial Surface of the same Hemisphere (front to right). 



This area is played upon by all the sensory and associa- 

 tive arrangements in the cortex. Like every other part of 

 the brain it receives and discharges impulses (fig. 89). But 

 unlike the receiving areas, which have been already considered, 

 it discharges outwards from the brain upon the spinal arcs. 



