4io 



Fig. 118 (from Sherrington, 1905, p. 277) shows some further points. In this 



case, the reflex con- 

 traction of the 

 muscle was brought 

 about by stimula- 

 tion of the skin of 

 the foot of the 

 opposite side, indi- 

 cated by the lower 

 signal. At the rise 

 of the upper signal, 

 the foot of the same 

 side as that of the 

 muscle observed 

 was stimulated. 

 The excitation of 

 the centre dis- 

 appears, and it is 

 to be noted that it 

 falls below the level 

 at which it was 

 before the reflex 

 contraction was in- 

 duced. The cells of 

 the centre were, 

 therefore, already 

 in a state of partial 

 tonic excitation 

 before the exciting 

 stimulus was ap- 

 plied, and this was 

 abolished along 

 with that due to 

 the stimulation 

 of the afferent 

 nerve. 



Fig. 119 (Veszi, 

 1910) is a some- 

 what simpler case, 

 being a reflex from 

 the spinal cord 

 separated from the 

 higher centres. 

 The gastrocnemius 

 muscle of the frog 

 is put into contin- 

 uous reflex tetanus, 

 by stimulation of 

 the afferent dorsal 

 root of the 9th 

 spinal nerve, dur- 

 ing the mark of 

 the lower signal. 

 At the se.veral 

 marks of the upper 

 signal, the central 

 end of the 8th root 

 was stimulated. 

 There is complete 



FIG. 118. REFLEX INHIBITION OF DECEREBRATE TONE. The tone was 

 induced by stimulation of the skin of the foot of the opposite 

 side, marked by the lower signal and by lines cutting the 

 myogram. During the time marked by the upper signal, the foot 

 of the same side as the muscle was stimulated. Note that the 

 muscle was, to begin with, in some degree of tonic contraction, 

 and that this is inhibited together with that due to the reflex 

 from the contralateral foot. The muscle falls to the position of 

 complete relaxation. 



(Sherringtou, 1905, Fig. 3.) 



