368 TITCHENER AND PYLE— ON THE AFTER-IMAGES [July 23, 



These observations would, no doubt, have been repeated, and 

 their interpretation discussed by other experimenters, had not Baird 

 pubHshed, earher in the same year, his study of the color sensitivity 

 of the peripheral retina. " There seems to be no doubt," Baird had 

 written, " that Hellpach's zone of complementariness is an artifact, 

 and that its discovery is wholly due to the experimenter's failure 

 to avoid retinal fatigue [chromatic adaptation] in his explorations." * 

 Nevertheless, one of the present writers (T) made in 1906 a fairly 

 long series of campimetrical observations (some 200 in all) with 

 the view of testing Miss Fernald's conclusion. The colored stimuli 

 were Hering papers, R, Y, G and B ; the backgrounds were white, 

 neutral gray and black. In no case was " exposure, beyond the lim- 

 its where any color is seen," followed by a colored after-image, clear 

 or obscure. All four colors, if they gave an after-image at all, 

 gave a colorless image, indistinguishable from the after-images of 

 gray stimuli — as these gray stimuli themselves were indistinguish- 

 able from the colored papers. It therefore seemed probable — in- 

 deed, it seemed practically certain — that the Mount Holyoke results 

 were due to a defect of method. Since Baird's disproof of the 

 " gegenfarbige Zone " was deemed complete and final, the Cornell 

 observations were not published. 



However, in the following year, 1907, a second paper from the 

 Mount Holyoke laboratory reported the same phenomenon. "At 

 the extreme periphery it sometimes happened: (a) that a stimulus 

 which was clearly seen produced no after-image. ...(b) On the 

 other hand there were 118 cases in which a subliminal stimulus pro- 

 duced an after-image which was perfectly distinct in color. . . . 

 That this somewhat unusual result was not the outcome of imag- 

 ination or suggestion seems proved by the fact that these invisible 

 colors gave rise to their appropriate after-images." ^ The authors, 

 the Misses H. B. Thompson and K. Gordon, found no indication 

 of Hellpach's zone of complementarism. They refer the images to 

 the enhancing influence of a light background. 



*J. W. Baird, "The Color Sensitivity of the Peripheral Retina," Carnegie 

 Institution of Washington, Publication No. 29, May, 1905, 73. 



° " A Study of After-images on the Peripheral Retina," Psychol. Review, 

 XIV., March, 1907, 126 f., 129 f. ■ 



