TABLE 24—CONTINUED
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 9 1
20 9 Same 10 0 10 0
21 10 Same 10 0 10 0
22 11 Same 10 0 10 0
23 June 1 Both varied from
1 to 1800 c.m. 12 8 10 10
24 2 Same 18 2 14 6
25 June 3 Both varied from
2 to 1800 c.m. 19 1 17 3
26 4 Same 17 3 17 3
27 5 Same 18 2 18 2
[Footnote 1: Brighter.]
[Footnote 2: Darker.]
These long-continued and varied tests with Nos. 151 and 152 revealed three facts: that the mice depend chiefly upon brightness differences in visual discrimination; that they probably have something which corresponds to our red-green vision, although their color experience may be totally unlike ours; and that the red end of the spectrum seems much darker to them than to us, or, in other words, that the least refrangible rays are of lower stimulating value for them than for us.
TABLE 25
GREEN-RED TESTS
June 1, 1906 No. 151
BRIGHTNESS VALUE IN CANDLE RIGHT WRONG
TEST POSITION METERS (GREEN) (RED)
1 Green on left Green 4, Red 448 Right —
2 Green on right Green 448, Red 4 Right —
3 Green on right Green 4, Red 448 Right —
4 Green on left Green 448, Red 4 Right —
5 Green on left Green 3, Red 1800 — Wrong
6 Green on right Green 1800, Red 3 — Wrong
7 Green on right Green 3, Red 1800 — Wrong
8 Green on left Green 1800, Red 3 Right —
9 Green on right Green 5, Red 34 Right —
10 Green on left Green 34, Red 5 Right —
11 Green on right Green 6, Red 74 Right —
12 Green on left Green 74, Red 6 Right —
13 Green on left Green 4, Red 448 — Wrong
14 Green on right Green 448, Red 4 Right —
15 Green on right Green 4, Red 448 — Wrong
16 Green on left Green 448, Red 4 Right —
17 Green on right Green 3, Red 1800 — Wrong
18 Green on left Green 1800, Red 3 — Wrong
19 Green on right Green 1800, Red 3 — Wrong
20 Green on left Green 3, Red 1800 Right —