208 Prof. C. S. Sherrington and Miss S. C. M. Sowton. [June 29, 



contraction is on the wane as judged by decline in the height of the myogram. 

 It shows itself also when the intercurrent contralateral stimulus is repeated 

 at a time when the reflex, as judged by the myogram curve, is exhibiting 

 no marked decline, but remains as high, or almost as high, as it was at outset. 

 It would seem, therefore, that, as the excitatory reflex proceeds, some central 



Fig. 6. — Semitendinosus (cat, decerebrate). At outset of the observation the muscle was 

 already in contraction owing to some reflex the origination of which was not clear. 

 The contralateral afferent (peroneal with popliteal) was then (left-hand notch of 

 signal) faradised ; this caused a transient increase of contraction, followed during 

 the stimulation by marked inhibition, and succeeded, on withdrawal of the stimulus, 

 by a rebound contraction. On repetition of this stimulus (middle notch on signal 

 line), a marked inhibition again occurred, but without initial increase of contraction 

 and followed after withdrawal of the stimulus by less marked rebound. On a third 

 repetition (right-hand notch of signal line) the stimulus caused inhibition even more 

 prompt than before, and no rebound contraction followed its withdrawal. Time 

 marked above in seconds. 



change ensues very soon after the reflex has reached its maximum, which 

 renders the reflex discharge more and more open to inhibitory decrement. In 

 other words, fatigue of the background reflex seems to favour markedly the 

 operation of inhibition against the reflex. 



Further, when the contralateral afferent under a given stimulus of weak 

 intensity produces the reflex augmentation of the background contraction 



