REACTION-TIME OF GONIONEMUS MURBACHII. 95 



the form of the stimulus, the threshold gives the longest and 

 most variable reaction-time which can be obtained by the use of 

 that particular quality of stimulus. Now, as the intensity of the 

 stimulus is increased the variability decreases. Why may we not 

 choose equality in relative or in absolute variability as a basis of 

 comparison ? If it should be found and I am now gathering data 

 for the settlement of the point that the relative variability is the 

 same for the threshold reaction-time to all qualities of stimuli, 

 equality in relative variability would be the most satisfactory 

 basis ; if, on the other hand, absolute variability is a constant 

 quantity at the threshold, it should be used in preference. 



NOTE. Reasons have recently appeared for returning to the 

 original spelling of the name of the medusa. Gonioncnnts there- 

 fore is used instead of Gonionenia. 



