1 May 7 Green Red 1800 c.m. 10 10 12 8 2 8 Same 12 8 11 9 3 9 Same 15 5 14 6 4 10 Same 18 2 12 8 5 11 Same 18 2 14 6 6 12 Same 19 1 16 4 7 13 Same 19 1 18 2 8 14 Same 20 0 20 0 Brightness tests without colors were now given to determine whether the mice had been choosing the brighter or the darker instead of the green. TABLE 26--CONTINUED NO. 2 NO. 5 SERIES DATE BRIGHTNESS VALUES RIGHT WRONG RIGHT WRONG (GREEN) (RED) (GREEN) (RED) 8a 14 Brighter 74 c.m. 0[1] 10[2] 2[1] 8[2] Darker 3 c.m. 9 15 3 c.m. on left 1800 c.m. on right 8 12 16 4 10 16 4 c.m. on left 36 c.m. on right 5 5 7 3 11 16 Green 4 c.m. Red 36 c.m. 9 1 8 2 12 17 11 c.m. on left 1800 c.m. on right 7 3 6 4 13 17 Green 11 c.m. Red 1800 c.m. 9 1 8 2 14 18 Mixed values 3 to 1800 c.m. 7 3 8 2 15 19 Same 7 3 7 3 16 20 Same 7 3 7 3 17 21 Same 7 3 9 1 18 22 Same 9 1 8 2 19 23 Same 7 3 9 1 20 24 Same 10 0 8 2 21 25 Same 10 0 9 1 22 26 Same 9 1 10 0 [Footnote 1: Brighter] [Footnote 2: Darker]