224 Journal of Comparative Neurology and Psychology. 



between yellow and greenish-yellow, never. Yet, even up to the 

 last day of the investigation, I could not induce the child, on show- 

 ing him white, to give the correct name; he said either "yellow" 

 or, more frequently, nothing — the same attitude, therefore, as 

 toward blue. 



I broke off my investigations on the fifteenth day, but intend 

 to renew them somewhat later; until then the child is not, if possi- 

 ble, to be questioned about colors. 



In reviewing the experiences of our fifteen days' experimentation 

 the following points appear to me to be worthy of note: 



1. In the very first systematic tests the child at once designated 

 as "red," not only the spectral red that he had learned to recognize 

 during the preliminary experiments, but likewise bright and dark 

 as well as unsaturated reds; he included in his choice also pink, 

 purple and, occasionally, orange. 



2. Green was learned without much practice and was not 

 afterward forgotten; similarly, a few days later, violet and black. 



3. The recognition of gray and blue developed rather more 

 slowly. 



4. Blue was forgotten again in two days; that is, the name was 

 not used, although the color was only very infrequently confused 

 with other colors. 



The first point is important because it shows that the child 

 grasped the concept "red" forthwith, quite independently of the 

 accidental brightness or saturation of the particular red in con- 

 nection with which he had at first been taught the name of the 

 color. This fact further clearly demonstrates that red-green 

 color-blindness could not have been present. From the very 

 beginning I had taken care that during the first week such colors 

 as green and gray, and especially brown, which dichromates con- 

 fuse with red, should be, in numerous variations, amply repre- 

 sented; the opportunity for the typical confusions was therefore 

 constantly present. Such confusion occurred, however, neither 

 at first nor later, when I kept introducing all sorts of combinations 

 of greens, browns, grays and pinks, in order to give him the chance 

 to confuse green too with the other colors, a confusion which not 

 only every dichromate, but likewise many "anomale" trichro- 

 mates would have fallen into. 



At first glance it might appear that the child's behavior 



