CEREBRAL MOTOR CONTROL 41 



Experiment 6 



Monkey 3. After the animal had recovered its normal motor ability 

 on the right side following the destruction of the left cortical motor 

 area, the right cerebral motor area was cauterized (July 28, 1916). 

 This produced a left hemiplegic condition similar to those in the other 

 experiments. 



Management and results. Both arms and legs were permitted to be 

 free to move, but the left paralyzed arm and leg were carefully mas- 

 saged without, however, giving individual attention to the special muscle 

 groups and to the nerves as had been done in the second part of the 

 preceding experiment. This animal continued to use the right arm 

 almost to the exclusion of the left, although both may now be used when 

 it is necessary, the left more awkwardly than the right. The animal 

 moves well, climbs and jumps, it has been seen to pick over its cage 

 companion for parasites (?), but all of its movements are more awkward 

 than those of monkey 2 which is in the same cage with it. There has 

 been a slight deterioration of the right side in that the right hand can- 

 not be used as well as at the end of the special training period, and 

 at the present writing it exhibits a slight wrist 'drop on the right side, 

 but a marked wrist drop on the left. When it handles food, which it 

 usually takes in both hands at one time, it is noticeable that there is 

 considerable weakness on the left, there is also a marked awkwardness. 

 During December, 1916, this animal was noticed to have convulsions. 

 One began December 18, 1916, at about 2.00 p.m., and the animal 

 was under observation during the convulsive attack. The animal had 

 been feeding, and was holding two bananas in his hands. The food was 

 suddenly dropped, and the monkey tried to get it from the floor, but 

 not being apparently able to do this with the hands, he lowered his head 

 to where the bananas had fallen. In that position a series of clonic 

 movements began. The animal fell to its side, and the convulsive 

 movements were noticed to be especially (or entirely, it could not be 

 said with certainty) of the right side, but the face area was not ap- 

 parently involved. The leg was more active than the arm, although the 

 arm shook all over and the fingers were also in alternate contraction 

 and relaxation. When the convulsion had partly subsided the animal 

 tried to crawl over a partition (about 35 cm. high) which separated the 

 cage into two parts. This attempt was unsuccessful at first, but the 

 monkey continued to try until it succeeded. Success was finally at- 

 tained only with great effort of the left arm and leg, and the right 



