CEREBRAL MOTOR CONTROL 37 



in the monkey's cage. The coordination and quickness for the per- 

 formance of this act will readily be appreciated. 



Summary. By preventing movement of the normal arm and then 

 "compelling" the animal to move the paralyzed segments, and by me- 

 chanical stimulation of the peripheral nerves and of the muscles, in 

 three weeks the animal recovered from its paralyzed condition to such 

 an extent that the movements on the paralyzed side were judged to be 

 normal. 



Experiment 2 



Monkey 1. A week after this annual had thoroughly recovered the 

 use of its right side a second similar operation was performed on the 

 right hemisphere. The whole of the right stimulable cortex was de- 

 stroyed under asepsis and general anesthesia, June 26, 1916. The 

 paralysis involved the left side of the face as well as the arm and leg, 

 and the paralysis was typical of the upper neuron type. 



Management and results. The right (recovered from paralysis) side 

 of the body was not restrained and the left half of the body was not 

 given any special treatment. In this respect the animal was given the 

 chance to recover by itself without interference. The animal usually 

 lived in a cage (90 by 58 cm., and 114 cm. high) by itself so that it would 

 not get the stimulus of combat, etc., with another animal, but it was 

 let out into a large room for exercise each day for periods varying from 

 one to four hours. Some forced exercise of the newly paralyzed parts 

 could not be prevented, for it was necessary to compel the animal to 

 come close for observation and for testing, and its solitary living had 

 made it somewhat timorous although during the period of its former 

 paralysis it had been handled with relative ease. The animal, there- 

 fore, cannot be said to have been entirely without some of the treat- 

 ment which had been given to it following its first hemiplegia, although 

 this kind of treatment was given as little as possible. 



Even though the animal had received a small amount of forced 

 exercise it has remained paralyzed and apparently without much capa- 

 bility of using its left arm and hand (December- 24, 1916). It can 

 walk and jump; it climbs on the wire netting of its cage, it uses the left 

 arm for a prop, and with the left hand takes hold of its strap when the 

 latter is pulled upon. It tends to fall towards the left side, when it 

 jumps it does not always reach the cage or box which it apparently 

 attempts to reach, when it climbs over its cage the right arm and hand 



