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.
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 —
Totals
12 8
