1912.] 



Instability of Cortical Points. 



259 



Fig. 5. 



Experiment 15, Callothriv, 5.2.12. — Record of a series of seventeen successive stimuli applied at the 

 same strength to the same flexion-point of the cortex. This demonstrates at first facilitation of the 

 reaction and an establishment of a state of maintained flexor contraction. After stimulus X the 

 reaction becomes diphasic, there being at first relaxation followed by contraction. This, which is 

 particularly well marked in the case of stimulus XII, shows a partial flexion reversal by repetition of 

 stimulation. 



contraction (fig. 6). This reversal, however, does not always take place; 

 sometimes the restimulation of the point tends to increase the contraction of 

 the muscle although it does at the same time lessen the clonic factor in the 

 epileptoid discharge while augmenting the non-clonic factor. 



