294 Journal of Comparative Neurology and Psychology. 



fifty pairs of reaction for each interval and each animal, which 

 were reinforced or inhibited furnishes an excellent quantity for 

 comparison with the averages. As such comparison reveals 

 close agreement between amount of influence of the auditory 

 stimulus and the number of reactions either reinforced or inhib- 

 ited it is clear that the averages are trustworthy, even though 

 the variability of the reactions is enormous. 



TABLE II. 



Influence of Sound on the Tactual Reactions of the Green Frog for 



Different Temporal Relations of the Stimuli. 



The results tabulated in Table II show that the sound when 

 occurring simultaneously with the tactual stimulus greatly in- 

 creases the amount of the reflex, while on the contrary it 

 decreases the amount of reaction if it precedes the tactual stim- 

 ulus by .5 to i.o". Number i, for example, exhibited reinforce- 

 ment equal to 62 % of the amount of the tactual reaction when 

 the stimuli were given simultaneously, but when the sound 

 occurred .65" before the touch the resulting reaction was 10 % 

 less than the tactual. 



In Figures 5 and 6 are curves, representing the amount of 

 reinforcement and inhibition for the four frogs, constructed 



