igoS.] 



OF SUBLIMINALLY COLORED STIMULI. 369 



Again, in 1908, in a continuation of her former study, Miss 

 Fernald writes : " In agreement with the observations already made 

 in our first paper, and later in the work of Miss Thompson and Miss 

 Gordon, our results show that in many cases a characteristic colored 

 after-image follows an unperceived color stimulus. In general this 

 after-image is perfectly clear and distinct. . . . That the phenomena 

 here described are genuine after-images is shown by the fact that 

 the color is in every case the color complementary to the stimulus 

 as [it would be] perceived either in central or in peripheral vision, 

 although the observer w^as kept in complete ignorance concerning 

 the nature of the stimuli employed, and so had no clew as to what 

 after-image was to be expected in cases in which the [color of the] 

 stimulus was not seen. Moreover, gray and white, though fre- 

 quently used as stimuli, were never followed by colored after- 

 images." ^ Hellpach here drops out of sight altogether, while the 

 range of the subliminally aroused after-image is extended, from 

 " the extreme periphery," to include both the B-Y and the R-G 

 zones. 



New Experiments. 

 I. Direct Vision: (a) Light-Adaptation. 

 Experiment I.: The Glass Wedge. — We washed to begin our 

 own experiments by repeating Tschermak's observation with the 

 faintly colored glass wxdge. However, the difficulty of finding a 

 suitable glass proved to be so great that this Exp. I. was, as a mat- 

 ter of fact, performed last of all. After many delays we were able, 

 through the kind assistance of Professor J. A. Brashear, to secure 

 a wedge of light blue glass, 5 by 20.5 cm., the thin end of which 

 was almost colorless in clear daylight. Although the color might 

 well have been still fainter, we found it possible, wnth an observation- 

 slit of 22 by 5 mm., and with a white muslin screen stretched be- 

 tween the glass wedge and the white-screened windows from which 

 our illumination was derived, to take observations of 2 to 5 min. 

 duration, in which the wedge was moved, for the practised observ- 

 ers, from 1.5 to 4 cm., and for the unpractised from 5 to 10 cm. 



• " Studies from the Bryn Mawr College Laboratory : The Effect of the 

 Brightness of Background on the Appearance of Color Stimuli in Peripheral 

 Vision," Psychol. Review, XV., January, 1908, 33 ff. 



