Nagel, Color-Sense of a Child. 225 



toward blue speaks for "tritanopia" (violet color-blindness), or 

 at least indicates a certain degree of weakness of the yellow-blue 

 sense. I believe that to be, however, an error. There is surely 

 no question there of tritanopia. The typical tritanopic confusion 

 between blue and green was not made, although several varieties 

 of green and of blue were often intentionally show^n him; nor did 

 any confusion between brown and unsaturated red manifest itself. 



The child's disinclination to name blue remains, nevertheless, 

 noteworthy and is not easily to be explained. Among the colored 

 squares some were to be found of a particularly fine and brilliant 

 ultramarine blue; but he pa d no attention to them. He showed 

 the same indifference when I gave him, on the tenth day, a 

 game to be played with colored blocks of red, green, blue, yellow, 

 black and white; all the other colors interested him more than 

 the blue. He recognized and named, at least during the first 

 days, the white blocks correctly. 



I think that the child's forgetting of the white, toward the end 

 of the period, may be partly due to the fact that I was not enabled, 

 at that time, to concern myself much with him and, in particular, 

 seldom questioned him about white. In addition to this, it may 

 also be that the newly-learned yellow had usurped in interest the 

 place of the white. 



With blue, however, the case is quite different. After he had 

 learned the name, on the eighth day, I took quite particular pains 

 to test him for ability to discriminate between blue, violet and green. 

 The child nevertheless used the term "blue," as I have already 

 indicated, only on the eighth and ninth days, avoiding it later 

 altogether. In point of time this change coincided with the acquisi- 

 tion of violet, for which, as well as for green and red, his interest 

 did not flag. Perhaps, therefore, the blue was crowded out by 

 the violet, the two colors having for the child a manifest similarity. 

 It was not a difficulty with the word itself, for he repeated the word 

 easily, when I pronounced it for him, at the same time frequently 

 pointing to some color with the w^ords: "that's surely not blue" 

 or "that may be blue — no, it isn't, either." 



It is, too, practically certain that the blue did not look particu- 

 larly dark or particularly unsaturated to the child's eye; if the 

 absolute stimulus-value had been specially low", if, in other words, 

 the color appeared too dark, there would have been danger of 

 confusing it with black or with dark green; such confusion did 



