Systematic training experiments were carried on with individuals of both the 200 and 400 lines of descent. For each of these lines a male and a female were trained at the age of four weeks to discriminate between the white and the black electric-boxes and to choose the former. After they had been thoroughly trained these individuals were mated, and in course of time a male and female, chosen at random from their first litter, were similarly trained. All the individuals were trained in the same way and under as nearly the same conditions as could be maintained, and accurate records were kept of the behavior of each animal and of the number of errors of choice which it made in series after series of tests. What do these records indicate concerning the influence of individually acquired forms of behavior upon the behavior of the race? TABLE 53 THE INHERITANCE OF THE HABIT OF WHITE-BLACK DISCRIMINATION Number of Errors in Daily Series of Ten Tests MALES FEMALES SERIES FIRST SECOND THIRD FOURTH FIRST SECOND THIRD FOURTH GENERA- GENERA- GENERA- GENERA- GENERA- GENERA- GENERA- GENERA- TION TION TION TION TION TION TION TION No. 210 No. 220 No. 230 No. 240 No. 215 No. 225 No. 235 No. 245 A 6 5 6 7 8 4 4 7 B 6 8 8 8 8 7 6 5 1 6 7 6 5 7 6 5 4 2 4 3 1 5 5 6 4 5 3 3 1 4 5 3 4 4 3 4 5 0 3 4 2 1 3 1 5 3 0 4 2 1 3 3 0 6 2 1 4 2 2 1 1 1 7 1 0 3 1 1 1 2 0 8 0 0 1 0 0 0 2 3 9 0 0 0 1 1 0 0 0 10 0 0 1 0 2 1 1 11 0 0 0 3 0 0 12 0 0 0 0 0 13 0 0 0 0 14 0