1909.] 



Innervation of Antagonistic Muscles. 



251 



(mechanical or electrical) of the central stump of almost any afferent nerve 

 of the ipselateral limh. If while this reflex contraction is in progress the 

 central stump of a nerve, e.g., popliteal, of the contralateral fellow limb be 

 suitably faradised, there ensues immediate relaxation of the contracting 

 semitendinosus (fig. 3). But if the contralateral afferent be stimulated while 

 the preparation is at rest there may be no evidence of inhibition or of any other 



Fig. 2. 



Fig. 2.— Keflex contraction of Vastocrureus muscle evoked by stimulation of central 

 end of contralateral peroneal nerve (C). Before this stimulation a stimulation of 

 the ipselateral peroneal (I) was commenced. This latter stimulation produced no 

 visible effect on the muscle, but it is only on its cessation that the contralateral 

 stimulation is able to produce a contraction. Cat, decapitated preparation. Time in 

 seconds above. 



Fig. 3.— Reflex contraction of Semitendinosus, a knee-flexor, evoked by stimulation of 

 central end of ipselateral peroneal nerve (I), and inhibited during concurrent 

 stimulation of contralateral popliteal nerve (C). Cat, decapitated preparation. 

 Time in seconds above. 



effect. The reflex stimulus might then be supposed not to be exerting any 

 influence whatever on the flexor muscle. That is because there is then in 

 the muscle no tonic or other contraction against which the reflex inhibition 

 can show. That the reflex inhibitory influence is, however, really at work 



T 2 



