274 Messrs. N. B. Dreyer and C. S. Sherrington. 



discharge of the reflex centre follows the full frequence-rate of the afferent 

 nerve stimulation, the centre emitting successive volleys of centrifugal 

 impulses at the same rate as those evoked in and transmitted to it by the 

 afferent nerve. 



(2) The finger, on touching the muscle-tendon, detects a slight thrill at 

 rates of stimulation of the afferent nerve even above 55 per second. To 

 test whether this thrill has the same frequency as the stimulation rate, a 



A 



B 



Fig. 2. — A, reflex contraction of tibialis anticus (spinal cat) to faradisation of afferent 

 nerve (popliteal), at 15 per sec, as signalled below. The period of unshortcircuiting 

 the second circuit is not shown, but the interrupter in primary circuit lapsed during 

 the time of unshortcircuiting, and just prior to that one of the interruptions missed, 

 and this irregularity the reflex tetanus has followed perfectly. B and C, similar 

 preparation from another experiment ; faradisation at 23 per sec. ; B, the reflex 

 response ; C, response to stimulation of motor nerve ; second coil at 18 cm. = 250 

 Berne units, for both. 



myograph recorder was prepared, whose vibration period was 65 per second 

 when attached to the contracted muscle, as tested by suddenly jerking^and 

 releasing it. The afferent nerve was then stimulated with a break-shock 

 series of 65 per second. The recording myograph was thus used as a 

 resonator for that pitch of vibration which should obtain in the muscle 

 under the stimulation used if the reflex harmonised with the afferent nerve's 

 stimulation. The result was that the myograph record then exhibited a 

 vibration of 65 per second thronghont the duration of each reflex tetanus. 



