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Prof. C. S. Sherrington. Nervous Rhythm [Feb. 3, 



by r. 14 than after inhibition by 1. 17. And when, in fig. 13, the r. and 1. 

 stimuli are applied synchronously (observation 50) and begin together, r. 

 stimulus obviously has the upper hand, for L muscle at once contracts, and 

 though not seen in the figure K muscle at once relaxed. Moreover on with- 

 drawing the two stimuli together L muscle at once relaxes instead of showing 

 rebound contraction. Clearly r. stimulus is stronger than 1. stimulus in its 

 effect on the preparation. Observations 50, 51, 52, 54, fig. 12, in which r. 

 and 1. stimuli are applied together, do not differ in result on the muscle 

 from observations 48 and 49, fig. 12, in which r. stimulus was applied 

 alone, except in the feature that some little while after commencement 



Fig. 13. — Extensor muscle of left knee L.V. Observations 49 and 50 show reflex 

 contractions evoked by stimulation of right peroneal nerve, r.p. Then 50-54, a series 

 of synchronous stimulations of r.p. and l.p. ; during these there ensues stepping ; 

 the inhibitory phase (flexion phase) of the step appears as a gradually increasing 

 inhibitory notch on the contraction caused by r.p. Time above in fifths of seconds. 



3f each of the double stimulations (observations 50-54) an inhibitory notch 

 ippears in the reflex contraction, whereas in observations 48 and 49 there is 

 nothing of the kind. Eeserving this point of difference for the present, the 

 result here is that of the two stimuli r. 14 and 1. 17 the former is the stronger 

 not only in its numerical scale-value but also as actually tested on the 

 preparation. Yet this pair of unequal stimuli give a good rhythmic reflex 

 during their concurrent application (figs. 1 and 13). If r. 14 and 1. 17 form 

 an unequal pair in which r. is the stronger, obviously r. 13 and 1. 16 must 



r 13 



form a pair more unequal still. Yet gi yes a g°°d rhythmic reflex in one 



of the muscles (fig. 13). 



Certainly, therefore, in order to produce the rhythmic reflex, the two 

 antagonistic stimuli, right and left, need not be exactly equally balanced 



