any of these experiments. No. 152 showed no ability
whatever to choose the green in the first of the series
(series 23 of Table 24) of which that of Table 25
is a sample. His record, 10 mistakes in 20 choices,
was even poorer than that of No. 151. That both
of these mice learned to choose fairly accurately
in these final tests is shown by the results of series
24, 25, 26, and 27. I must admit, however, that
these records indicate little ability on the part of
the animals to discriminate colors.
GREEN-RED TESTS
Brightnesses Extremely Different for Human Eye
Intensities are given in candle meters (c.m.)
NO.
151 NO. 152
SERIES DATE CONDITIONS
RIGHT WRONG
RIGHT WRONG
(GREEN) (RED)
(GREEN) (RED)
1 April 26 18 c.m. on left
1800 c.m. on right 11 9 7 13
2 27 Same 16 4 16 4
3 28 Same 20 0 17 3
4 29 Same 19 1 19 1
5 30 Green 18 c.m.
Red 18 c.m. 9 1 10 0
6 30 Green 64 c.m.
Red 18 c.m. 9 1 8 2
7 May 1 Green 6 c.m.
Red 1500 c.m. 7 3 9 1
8 1 Green 4 c.m.
Red 1500 c.m. 8 2 7 3
9 2 Both varied from
4 to 1500 c.m. 18 2 18 2
10 3 Green 2 c.m.
Red 1800 c.m. 6 4 7 3
11 3 Same 10 0 10 0
12 4 Same 7 3 8 2
13 4 Same 8 2 6 4
14 5 Green 1 c.m.
Red 1800 c.m. 19 1 19 1
Filters were now removed. An illumination of
15 c.m. was established on one side and an illumination
of 0 on the other side, in order to ascertain whether
the mice would choose the brighter box. This was
done to test the assumption that the green in the
previous tests had always appeared brighter to the
mice than did the red, and that in consequence they
had chosen the brighter box instead of the green box.
No.
151 No. 152
SERIES DATE CONDITIONS RIGHT WRONG
RIGHT WRONG
(GREEN)
(RED) (GREEN) (RED)
15 May 5 Brighter 15 c.m.
8[1] 2[2] 10[1] 0[2]
Darker 0 c.m.
16 5 1 c.m. on left
1800 c.m. on right 10 0
10 0
17 5 1 c.m. on left
0 c.m. on right 9 1
4 6
18 5 Green 18 c.m.
Red 18 c.m. 19 1
17 3
19 9 Same 9 1
