■278 Journal of Comparative Nc2iTology and Psychology 



I. The Vorxr.-HEi.MHiii.TZ Theory of Coh^r-Mixture. 



Statement. 



There are three fundamental col- 

 ors : red, green, violet. 



Colored light is not a simple but a 

 complex sensation, it results from a 

 mixture of colored lights. 



Response. 



Contrary to psychological color 

 analysis and to observation. 

 No explanation is given for : 



1. peripheral color-blindness. 



2. color-blindness in case of feeble 

 illumination. 



3. total color-blindness. 



n. Theories of Contrast Colors of Herixg, Mullek and Ebbingh.\L'S. 



There are four fundamental colors 

 red, green, yellow, blue. 



There are two pairs of contrasting 

 colors : red-green and vellow-blue. 



See below. 



Colorless light sensations result from 

 the function of a retinal black-white 

 visual pigment (Herixg) or through 

 cortical processes (Mui.LER) if two 

 contrast colors have mutually neu- 

 tralized each other. 



III. Theories that Colorless-Light Sensations are Produced by the Func- 

 tion> of the Rod-Pigment. 



The facts of the color systems, par- 

 ticularly that the two types of red- 

 green blindness are deficiency phe- 

 nomena, are not taken into considera- 

 tion. 



Mixtures of red and green do not 

 produce colorless light. 



Psychological analysis demands the 

 existence of four different fundamen- 

 tal sensations. 



It is not probable that two sensa- 

 tions subjectively completely similar 

 would be produced by two totally 

 diverse retinal processes. 



There are three color-sensations 

 which are produced by the activities 

 of the cones (v. Kries) or the de- 

 composition of the visual purple and 

 the retinal pigment (K(")Xii;). Color- 

 less light sensations arise in two 

 ways: by irritation of the rods or by 

 combination of more than one color 

 process. 



IV. C. L. Fraxklix's Theory of Molecular Dissociation 



There are four fundamental color 

 sensations, which are produced by 

 partial decomposition of difterentiated 

 molecules of the photo-chemical reti- 

 nal substance of the cones. 



Colorless light sensations are pro- 

 duced by I; complete decomposition See below, 

 of the undifferentiated rod molecule, 

 2) of the differentiated cone molecule. 

 The dichromasy of the normal retinal 

 periphery and the majority of cases 

 of partial color-blindness form an in- 

 termediate stage in the development. 



