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A TEXTBOOK OF PHYSIOLOGY 



moved, when his eyes are shut. Ablation of other regions of the cortex 

 have no effect upon the motor mechanism. 



The Results of Stimulation. If the brain be stimulated with an 

 adequate stimulus in the regions shown in Fig. 438, co-ordinated 

 movements of the corresponding parts are evoked on the opposite 



side of the body. Too strong a stimulus leads to a spread in 

 orderly sequence to the neighbouring areas. At first the con- 

 tractions are tonic in character, but later these are superseded 

 by contractions of a clonic nature. This is what takes place in 

 cortical epilepsy, the convulsive symptoms of which proceed in 



