2 4 o COMPARATIVE PHYSIOLOGY OF THE BRAIN 



The difference between Flourens's and Schrader's 

 observations lies in the fact that Flourens considered 

 this condition permanent, while Schrader showed that 

 it lasts only a few days or until the " shock-effect " of 

 the operation has passed off. The objection might 

 be raised that Schrader did not entirely remove the 

 hemispheres, but this was not the case. Schrader's 

 experiments are masterpieces in regard to the perfec- 

 tion of the mode of operation. The contradiction in 

 the statements of the two authors is due to the fact, 

 as it so often is in brain-physiology, that the minor 

 effects of the operation in one case were strong, in 

 the other slight, or that one author based his opinion 

 upon the most severe disturbances, the other upon 

 the slightest disturbances. The latter is the only re- 

 liable method in physiology of the brain, because in 

 addition to the disturbances caused by the loss of 

 part of the brain, the shock-effects on the rest of the 

 central nervous system also appear in the mosaic of 

 symptoms. Schrader's experiments are models in 

 regard to technique, but this cannot be said of 

 Flourens's experiment, to which fact the excellent 

 investigator Magendie vainly called attention. 



In Schrader's experiments, a few days after the 

 operation, spontaneity not only returns, but is evert in- 

 creased. The animal wanders about in tJie room un- 

 tiringly the greater part of the day. It is not blind, 

 for its movements are determined by visual impres- 

 sions. Like the frog without cerebral hemispheres, it 

 turns out to avoid obstacles. " Dusty window-glass, 



