INORGANIC RESPONSE 137 
of restitution. The response-curve thus rises to its 
maximum, after which the deflection is held as it were 
rigid, so long as the vibration is kept up. 
It was found that increasing intensities of single 
stimuli produced correspondingly increased responses. 
The same is true also of groups of stimuli. The maximum 



Fic. 87.—Cycric Curve rok Maximum Errects sHowInG HysTERESIS 
effect produced by superposition of stimuli increases 
with the intensity of the constituent stimuli. 
Hysteresis.—Allusion has already been made to 
the increased responsiveness conferred by preliminary 
stimulation (see p. 127). Being desirous of finding out 
in what manner this is brought about, I took a series 
