The Sense of Sight : Color Vision 149 



Further color tests with reflected light were made with 

 violet and red. Two dancers, Nos. 998 and 7, neither of 

 which had been in any experiment previously, were subjected 

 to the ten series of tests whose results are to be found in Table 

 21. In this experiment the cardboards used had been coated 

 with shellac to obviate discrimination by means of odor. 

 It is therefore impossible to give a precise description of the 

 color or brightness by referring to the Bradley papers. 1 

 Both the violet and the red were rendered darker, and ap- 

 parently less saturated, by the coating. 



These violet-red tests were preceded by two series of prefer- 

 ence tests (A and B), in which no shock was given and escape 

 was possible through either electric-box. Although the re- 

 sults of these preference tests as they appear in Table 21 seem 

 to indicate a preference for the red on the part of No. 998, 

 examination of the record sheets reveals the fact that neither 

 animal exhibited color preference, but that instead both 

 chose by position. Number 998 chose the box on the right 

 15 times in 20, and No. 7 chose the box on the left 15 times 

 in 20: 



Ten series of tests with the violet-red cardboards failed to 

 furnish the least indication of discrimination. The experi- 

 ment was discontinued because the mice had ceased to try 

 to discriminate and dashed into one or the other of the boxes 

 on the chance of guessing correctly. When wrong they 

 whirled about, rushed out of the red box and into the violet 

 immediately. They had learned perfectly as much as they 

 were able to learn of what the experiment required of them. 

 Although we are not justified in concluding from this experi- 

 ment that dancers cannot be taught to distinguish violet 

 from red, there certainly is good ground for the statement 



1 The violet was darker than Bradley's shade No. 2, and the red was 

 lighter than Bradley's red. 



