1913.] arising f rom Rivalry of Antagonist ic Reflexes. 249 



More satisfactory for comparison is fig. 8 with fig. 5. Both are observa- 

 tions from the same experiment, with no long interval between them. The 

 1. stimulus was of the same value in both, namely, 16 cm. But the 

 r. stimulus had value 15 "5 cm. in the observation fig. 8, whereas in that 

 of fig. 5 its value was 13 cm. The results contrast in three striking 

 features. Where r. stimulus is stronger (fig. 5) the rate of stepping is six 



Fig. 8. — Reflex reciprocal stepping as exhibited by isolated extensor muscle of knees, 

 right and left, evoked by concurrent stimulation of antagonistic afferents, right and 

 left peroneals, r.p. and l.p. Decerebrate cat. Time above in fifths of seconds. 



Compare fig. 5. Explanation in text, p. 249. Stimulus value r jP' ^ 5 cm ' . 



double phases in 4*8 sees., as against four double phases in 4 sees., where 

 r. stimulus is weaker. Where r. stimulus is weaker (fig. 8) the stepping is 

 not so well maintained as where r. stimulus is stronger. Where r. stimulus 

 is weaker (fig. 8) the stepping occurs in the fellow muscle of the right side as 

 well as in the left, and where r. stimulus is stronger (fig. 5 ) the stepping is 

 confined to the left-side muscle. 



3. Influence of Intensity-ratio between the two Antagonistic Stimuli. 



From the' preceding section it is clear that as might be expected the 

 proportion between the intensities of the two antagonist stimuli is an 



