230 'Journal of Cojnparative Neurology and Psychology. 



between red-colored and yellow-colored papers, absolutely no 

 conclusions can be drawn with regard to his color-sense; he may 

 equally well be normal, red-blind or green-bhnd. On the other 

 hand, it needs most certainly a normal color-visign, for one who is 

 quite without practice, to distinguish a red (even when little 

 saturated) from a brown colored paper. I feel compelled 

 especially to emphasize this point because it has been quite dis- 

 regarded in numberless researches in color-physiology, and because 

 this neglect has bred such great confusion, robbing not only pre- 

 vious observations on the color-sense of children, but also, and 

 especially, those on the color-vision of animals of much of their 

 worth and of their interest. 



TABULAR VIEW OF THE EXPERIMENTS. 



First day 

 Second day 

 Third day 

 Fourth day 

 Fifth day 

 Sixth day 

 Seventh day 



Eighth day J 



Ninth day 

 Tenth day 

 Eleventh day ~1 

 Twelfth day 

 Thirteenth day > 

 Fourteenth dav 

 Fifteenth day J 



Systematic practice in selection of red. 

 Occasional naming of the term ^^ green.'" 



Futile attempts to teach "blue"'; green always correctly recognized and named 

 without further practice. Blue, black and white now learned. 



Blue correctly recognized and named; no confusion of it with violet or green. 

 Occasionally naming of "yellow," which was not, however, retained. 



Violet now learned. 



Gray now learned; "blue"' no longer called by name. 



The term "white^' employed more and more seldom; "yellow^' even oftener and 

 more correctly. Red, green, violet, gray, black correctly named; blue and 

 white, while not often confused with other colors (violet or yellow), never- 

 theless never spontaneously named. Purple, at first called "red," now 

 usually called ^'violet." 



