1911.] On Reflex Inhibition of the Knee Flexor. 203 



although quite distinct and unmistakable. The contraction which weak 

 stimulation of the contralateral afferent thus produces tends, while the 

 stimulation is in progress, to subside and be replaced by inhibitory relaxation. 



Fig. 1. — Inhibitions of the knee flexor, semitendinosus (cat, decerebrate). Lower signal 

 marks stimulation (faradic) of ipsilateral afferent (peroneal + popliteal) exciting 

 reflex contraction of the muscle. This stimulus remains of the same intensity, 

 namely, 60 units of the scale of the Kronecker inductorium, in all three of the 

 successive observations or, b, and c. Upper signal marks stimulation (faradic) of the 

 contralateral afferent (peroneal + popliteal) ; this intercurrent stimulus is stronger in 

 b than in a, and in c than in b, the secondary coil being at 14 cm. in a, at 10 in b, 

 and at 6 in c. Time, in seconds, above. 



The result given by the intercurrent stimulus then is an initial contraction 

 followed by an ensuent inhibition (fig. 3, d). As the strength of the stimulus 

 is increased, the initial contraction becomes more brief and less ample, and the 

 ensuent inhibition appears earlier and is more pronounced. By further 



VOL. LXXXIV. — B. Q 



