32 APES, MONKEYS, AND LEMURS 



In addition to these attempts to determine "Sally's" capacity for numbers, 

 Dr. Romanes instituted a series of experiments designed to test her powers of 

 recognizing and distinguishing between colors. "It appeared to me," says the 

 experimenter, ' ' that if I could once succeed in getting her to know the names of 

 black, white, red, green, or blue, a possible basis might have been laid for further 

 experiments wherein these five colors could have been used as signs of artificially 

 associated ideas. The result, however, of attempting to teach her the names of 

 colors has been so uniformly negative that I am disposed to think the animal must 

 be color-blind. The method adopted in these experiments was to obtain a number 



SIDE VTBW OF HEAD OF CHIMPANZEE " MAFUKA." 



of brightly and uniformly colored pieces of straw each piece being either white, 

 black, red, green, or blue. Offered the straws two by two of different colors on 

 each occasion, the ape was invited to select the straw of the color named from the 

 one whose color was not named, and, of course, on choosing correctly was rewarded 

 with a piece of fruit. In this way she quickly learned to distinguish between the 

 white straws and the straws of any other color ; but she never could be taught to 

 go further. Now the distinction between the white straws and the straws of any 

 other color is a distinction which can be drawn by an eye that is color-blind ; 

 and from the fact that the ape is always able to perceive this distinction, while she 



