272 Mr. Graham Brown and Prof. C. S. Sherrington. [Mar. 16, 



Fig. 18. Fig. 19. 



Experiment 15, Callothrix, 4.3.12. — From the same experiment as the last, but here the 

 E stimulus (E — F) is first applied, and during its application the F stimulus (C — D) is 

 given. Here the extensor contraction is cut down during the F stimulus, and the flexor 

 relaxation gives place to contraction. At the cessation of the F stimulus the flexor 

 relaxation and extensor contraction are re-established. 



Experiment 15, Callothrix, 4.3.12. — In this record the F stimulus is first applied, and 

 the E stimulus is applied later during its application. The E stimulus here does not so 

 markedly antagonise the F reaction as in fig. 17. The extensor tonus is re-established 

 and the flexor relaxes, but not to the level which obtained before the first stimulus was 

 applied. 



in this manner sought to see the effect on the reactions of one point produced 

 by intermittent stimulation of its antagonistic point. Figs. 17, 18, 19, 20 

 illustrate the effect. The F point stimulated intermittently during the 

 stimulation of an E point may antagonise that action and establish its own. 

 The E point acting during the action of an F point may similarly break 

 through the F point response and establish its own effect. But there is 

 evidence that in such cases the intercurrent point does not get its full play, 

 in other words that there is some algebraic summation of the two opposed 

 actions. 



When the stimulations of E point and F point are nearly balanced there 



