RECORDS. 195 



causes a reflex reaction, but in case of other modes of stimula- 

 tion it is possible that beyond a certain point increase in inten- 

 sity of the stimulus causes slower and more variable reactions. 



Since the time of reaction varies with the intensity of the 

 stimulus it is useless to compare reaction times for different 

 modes of stimulation, or those of different species or individuals, 

 unless the relative variability is known. It is not improbable 

 that careful investigation of the relation of relative variablity to 

 reaction time will furnish a satisfactory basis for the accurate 

 comparison of different results. To say that one person reacts 

 more quickly than another to a given stimulus without taking 

 into account the variability of the reaction time is meaningless. 



Dr. Montague said that a psychosis, like all systems, possesses 

 in its totality a form or structure which is distinguishable, as the 

 perceiving subject, from its individual contents, as perceived ob- 

 jects. Changes in the individual contents produce concomitant, 

 though generally lesser, changes in the totality. The segment 

 of duration or change perceived in any one moment is not itself 

 a real change, but simply the ratio of the change-rate of the in- 

 dividual contents to the change-rate of the totality, at that inonient ; 

 and this ratio, though finite and variable, does not itself require 

 a finite time for its reahzation. Each unextended moment of 

 " real " time is thus adequate for the appreciation of an extended 

 period of perceptual or " specious " time. 



The paper of Messrs. Cameron and Steele reported the re- 

 sults of a series of experiments dealing with the effect of prac- 

 tice on the Poggendorff illusion, (i) Quantitative determina- 

 tions were made with a number of illusions ; (2) practice with 

 one illusion was carried on for an extended period ; (3) deter- 

 minations were again made with all of the illusions which were 

 used before the practice series. 



The apparatus used was demonstrated. The results show 

 that the illusion tends to disappear after a period of seven 

 weeks' practice. The effects of such practice were found to 

 hold good for figure other than that which the practice was made. 



The paper of Dr. Judd reported a series of quantitative de- 

 terminations of the amount of illusion in the Zollner figure 



