The results of the tests appear in Table 15. No record of the choices in the first two of the 17 series was kept. The totals therefore include 15 series, or 300 tests, with each individual. Neither the daily records nor the totals of this table demonstrate choice on the basis of color discrimination. Either the dancers were not able to tell one box from the other, or they did not learn to go directly to the orange box. It might be urged with reason that there is no sufficiently strong motive for the avoidance of an incorrect choice. A mistake simply means a moment's delay in finding food, and this is not so serious a matter as stopping to discriminate. I am inclined, in the light of result of other experiments, to believe that there is a great deal in this objection to the method. Reward for a correct choice should be supplemented by some form of punishment for a mistake. This conclusion was forced upon me by the results of these preliminary experiments on color vision and by my observation of the behavior of the animals in the apparatus. At the time the above tests were made I believed that I had demonstrated the inability of the dancer to distinguish orange from blue, but now, after two years' additional work on the subject, I believe instead that the method was defective. The next step in the evolution of a method of testing the dancer's color vision was the construction of the apparatus (Figures 14 and 15) which was described in Chapter VII. In connection with this experiment box the basis for a new motive was introduced, namely, the punishment of mistakes by an electric shock. Colored cardboards, instead of the white, black, or grays of the brightness tests, were placed in the electric-boxes. TABLE 15 ORANGE-BLUE TESTS, WITH FOOD-BOX MOUSE A MOUSE B SERIES DATE 1904 RIGHT WRONG RIGHT WRONG (ORANGE) (BLUE) (ORANGE) (BLUE) 1 Dec. 6 -- -- -- -- 2 7 -- -- -- -- 3 8 12 8 12 8 4 9 10 10 9 11 5 10 15 5 10 10 6 11 10 10 12 8 7 12 9 11 9 11 8 13 10 10 9 11 9 14 12 8 12 8 10 15 13 7 12 8 11 16 13 7 10 10 12 17 12 8 10 10 13 18 11 9 10 10 14 19 13 7 8 12 15 20 13 7 9 11 16 22 14 6 12 8 17 23 10 10 9 11 TOTALS 177 123 153 147