RESEARCHES BASED UPON THE THEORY 



235 



Bruckner and Kirsch^ found that the chromatic action time (v. 

 p. 91) for deuteranopes, especially for red and green, is considerably 

 greater than for normal trichromats. No experiments of this nature 

 have been made upon protanopes. 



^00 



50 



500 



50 



600 



50 



Fig. 67. Curves of discrimination sensibility for hues of the interference spectrum 

 of the arc light for two deuteranopes. x Neutral point. (Steindler.) 



III. Anomalous Trichromatic Vision 

 Approximate Dichromatism 



When the anomalous trichromats were discovered by Lord Rayleigh 

 the natural assumption was that the two groups correspond to the 

 protanopes and deuteranopes, but that the defect is partial instead of 



1 Ztsch.f. Sinnesphysiol. XLVi. 229, 1911. 



