DYNAMOGENIC INFLUENCE OF LIGHT 359 



E. M. was an undergraduate student in Case School of Applied 

 Science with about one year of previous experience as observer 

 in psychological work. He is slightly neurasthenic in type. 



F. F. and E. M. K. were unmarried female stenographers of 

 high school training. 



L. T. T. and H. M. J. were psychologists, and P. W. C. a 

 physiologist with long training and experience in psychological 

 work. 



L. Z>., L. S., H. D. and /. L. were undergraduate students in 

 the college for women of Western Reserve University, as was also 

 C. C. M. S. was an unmarried woman of about 19, a high school 

 graduate, not employed outside her own home. The two sub- 

 jects mentioned last were reactors in another experiment 6 in 

 the report of which they are designated as C and M respectively. 

 In that report, C. C. is erroneously described as having exhibited 

 in this experiment a better performance in the dark than in the 

 light. The assertion was based, not on the original data, which 

 I had not then seen for two years, but on a tabulation prepared 

 by an assistant, who had inadvertently transposed the headings 

 of two columns of scores. I take this occasion to make the 

 correction. 



G. P. L. was a physicist, with considerable experience in as- 

 tronomical observation and in stellar photography. 



The idiosyncrasies of certain subjects should be mentioned. 



M. S. exhibited some emotional instability, in the direction of 

 excessive timidity, aversion to taking the initiative, distrust of 

 her own judgment, etc., which were occasionally excited by inci- 

 dents of her engagement. She asserted both of this and the 

 experiment mentioned above, that she felt slightly ill at ease in 

 the dark, and enjoyed working in the light more. She was un- 

 certain of her judgment of relative speed of work under the two 

 conditions. 



E. M. K. preferred the light, but reported that she could " con- 

 centrate better" in the dark, and thought her performance in 

 the dark was superior. E. S. gave an almost identical report. 



6 Johnson, H. M. : The influence of the distribution of brightnesses over the 

 visual field on the time required for discriminative responses to visual stimuli. 

 This Journal, 1918, i, 459-494. 



