MOTOR FUNCTIONS OF CEREBRAL CORTEX OF CAT 197 



pupils, movements of the eyes, lids, nictitating membranes, re- 

 traction of the tongue, and movements of the head on the neck. 



The anterior bank of the left crucial of cat 15 gave the fol- 

 lowing results (fig. 17D). Stimulation of the region lying imme- 

 diately within the visible margin of the crucial sulcus, resulted in 

 dilatation of the pupils, retraction of the tongue, movements of 

 the lips. Stimulation of the outer margin of the field resulted in 

 retraction of the tongue, movements of the lids, mandible, lips 

 and flexion of the fore limb. Stimulation of the middle portion 

 of the field resulted in movements of the eyes and mandible, 

 retraction of the tongue and flexion of the fore limb. 



The order of mention of the various types of movement fol- 

 lowing stimulation of the banks of the crucial sulci is the order 

 of the frequency of their actual occurrence. 



CHARACTERS OF MOVEMENTS FROM CORTICAL STIMULATION 



The results obtained from the stimulation of the cortices of cats 

 8, 9, 10, 11, 12, 14 and 15 were analysed as to the types of the 

 movements produced and the points on the cortex from which 

 each type of movement originated. The accompanying table 

 (table 1) gives a list of these movements and figures 18 to 61 

 illustrate the cortical locations for each type. Four right and 

 four left hemispheres are included. 



The total number of successful stimulations of the eight hemi- 

 spheres was 467. Of these 154, or 33 per cent, were of the right, 

 and 313, or 67 per cent, were of the left cortices. The number of 

 the successful stimulation for each animal was as follows : right 

 hemisphere cat 8, 34; cat 9, 39; cat 10, 39; cat 12, 42; left hemi- 

 spherecat 10, 31; cat 11, 99; cat 14, 131; cat 15, 52. It was 

 found that a total of 903 segmental movements (i.e., movements 

 relating to single segment) of all types resulted from these stimu- 

 lations, of which 306, or 34 per cent, were from the right, and 

 597, or 66 per cent, from the left cortices. The number of these 

 movements for the individuals was as follows: right cat 8, 95, 

 or 2.79 individualized movements per stimulation; cat 9, 70, or 



