34 ROBERT OGDEN AND SHEPHERD IVORY FRANZ 



in preference to those of the paralyzed side even though the 

 latter be " recovered." And also, when the animal is under the 

 influence of certain toxic agents, such as alcohol or ether, the 

 previously paralyzed limbs exhibit motor disturbances even 

 though prior to the administration of the alcohol or ether the 

 animal appeared to be perfectly normal in a motor way. The 

 recovery in the monkey and ape is less rapid than in the dog, 

 although after nine to twelve months it may not be possible on 

 casual inspection to notice any motor disturbances. 3 



The effect of suitable exercises in the long-standing human 

 hemiplegics suggested that if the paralyzed segments of an ani- 

 mal with an experimentally produced hemiplegia were ade- 

 quately dealt with the recovery would be more rapid and more 

 complete than if the animal were permitted to recover by itself. 

 The suggestion was tested and the results of the observations 

 are given in the subsequent paragraphs. 



Four male monkeys (macacus rhesus) about a year and a half 

 old were successfully used as subjects. One other animal died 

 too soon after the operation to make the results of value. The 

 hemiplegia was produced under ether anesthesia by the destruc- 

 tion of the motor cortex with an electric thermocautery. The 

 extent of the motor area was determined by faridization (bi- 

 polar), and the area destroyed corresponded with the electrical 

 delimitation of the motor zone. After the destruction different 

 parts of the destroyed area, and beyond, were stimulated to 

 see if the electrical stimulations would then produce move- 

 ments, and in one case in which movements were obtained the 

 area of destruction was extended and the part already cauter- 

 ized was gone over again with the cautery. To destroy the 

 motor zone lying concealed within the central fissure the white 

 hot cautery was pushed about 6 to 8 mm. into the brain substance 

 and carried close to and parallel with the fissure. 



The lesions which were produced were different from those 

 produced by cerebral hemorrhage in man (apoplexy) in that they 



3 For a general account of the phenomena of recovery from cerebral paralysis 

 in the dog and monkey see Luciani: Human Physiology (Trans, by F. A. Welby), 

 vol. 3, pp. 581 ff. (dog) and pp. 586 ff. (monkey). 



