200 JOSEPH DUERSON STOUT 



and extension of the joints of the fore and hind limbs, including 

 the hip, but excluding the shoulder owing to complexity of the 

 movements of this latter joint. From stimulation of the eight 

 cortices there was a total of 441 flexions, of which 122 were from 

 stimulation of the right side and 319 from stimulation of the 

 left side. Comparing these with the total number of movements 

 of all types, the flexions are 40 per cent of the activity for the 

 right cortices and 53 per cent for the' left. There was a total 

 of 145 extensions from the eight cortices, of which 60 were from 

 the right side and 85 from the left. Comparing these with the 

 total number of movements of all types, from these cortices, 

 we see that the extensions are 20 per cent of the total activity 

 of the right and 14 per cent of the activity of the left cortices. 

 Average for the two sides 16 per cent. 



Combining the two sets of figures we find that of the total num- 

 ber of movements of all kinds, following stimulation of the right 

 cortices, a total of 60 per cent is either flexion or extension of 

 some one of the joints considered, and of the left cortices a total 

 of 65 per cent is either flexion or extension of these joints. The 

 flexions are slightly over three times as numerous as are the ex- 

 tensions, being twice as numerous on the right side and nearly 

 four times as numerous on the left side. In cat 10 the flexions 

 were 47 per cent of the activity of the right cortex and 76 per 

 cent of that of the left; average for the two sides, 58 per cent. 

 The extensions were 17 per cent on the right, and 12 per cent on 

 the left; average for the two sides 15 per cent. Flexions and ex- 

 tensions together were from the right cortex 64 per cent and 

 from the left cortex 88 per cent, for the two cortices an average 

 as compared with the total activity, of 74 per cent. 



In tables 1 , 4, and 5 the first columns show the numbers of the 

 diagrams which refer to the other data on the corresponding 

 lines on these tables. The remainders of the tables are almost 

 self-explanatory. 



Tihe study of the actual distributions of the cortical 

 points, the stimulation of which results in the production of 

 various types of body movements, brings out several interesting 

 facts. 



