DISTANCE IN THE SELECTION OF A PATH 



251 



other. The influence of habitual action is clearly seen hi that 

 the relative difference between long and short paths could be 

 rapidly increased without adjustment until the ratio of long to 

 short path was 2.11. Since the rat had previously as small a 

 fraction of noticeable difference as 12/100, additional trials, 

 after failure at 6/100, doubtless would again have led to adjust- 

 ment at 12/100. By gradually increasing the relative difference 

 between the lengths of the two paths and limiting the number 

 of trials habitual action rather than length of path seemed to 

 determine the rat's course. 

 Experiment 4. Maze B; rat 4. 



TABLE 4 



This rat gives a fraction of noticeable difference equal to 12/100 

 and failure at 6/100. The adjustment to 12/100 is further con- 

 firmed by the fact that after failure at 6/100 an increase to 12/100 

 again brought out the tendency to take the shorter path, and 

 was sufficiently effective to break the rat's habitual tendency 

 towards the left and bring about a change to the right. Again, 

 a shift of food-box from right (after adaptation) to left is followed 

 by an immediate tendency towards adjustment at 12/100. 



Experiments. Maze B; rat 5. 



Adjustment to 12/100 and failure to adjust (in the trials given) 

 to 6/100 is shown. 



