52 THOMAS WILLIAM BROCKBANK 



trials per day group, and Table X, of the one trial per day 

 group, presenting records of time, will serve to indicate 

 to some extent the effect which was produced by the diffi- 

 culty of establishing integration at the locus of dominant 

 " error." Each table presents the complete time records 

 of three rats, the first three columns (a, b, and c) containing 

 records of the poorest individual of the group, the second 

 three columns containing records of the best, and the last 

 three columns containing records of the second best. In 

 the respective columns, records 2, 4, and 8 in Table IX 

 correspond to records 2, 4, and 8 in Table XI; records 

 5, 9, and 8 in Table X correspond to records 5, 9, and 8 in 

 Table XII. Column "a" presents time in seconds from the 

 moment the rat entered the problem until it stepped on 

 the plane; column " b " presents time in seconds from the 

 moment the rat stepped on the plane until it entered the 

 food box; and column "c" is the total time. The effect of 

 the dominant " error " may be seen in column "a" where 

 the time is considerably greater than in column " b." The 

 distance from the entrance of the problem to the plane 

 is approximately equal to the distance from the plane to 

 the entrance of the food box; or, in other words, the distance 

 the rat must cover to produce the time of column "a" is 

 approximately equal to the distance the rat must cover 

 to produce the time in column " b." But the rat must ex- 

 ercise the integration of stepping on the plane before the 

 time of column "a" is recorded; and the difficulty of exer- 

 cising this integration of stepping on the plane frequently 

 called forth such responses as merely touching the plane, 

 going round the plane, etc., which greatly increased the 

 time of column " a." These records of time thus give some 

 intimation that the locus of dominant " error " is at the 

 plane. 



Table XI contains perfect trials and time in the first 

 fifteen trials of redintegration and the last fifteen trials of 

 learning for the three trials per day group at the 70-day 

 retention period. Table XII contains a like summary for 

 the one trial per day group at the 70-day retention period. 

 One rat of each group failed to complete learning; and 

 three of each group failed to begin the norm in redintegra- 

 tion within 30 trials. According to these tables the averages 



