EFFECT OF LENGTH OF BLIND ALLEYS ON MAZE LEARNING 39 



two trials, during which there was considerable random activity 

 and reduction of excess movements. It would seem that at 

 first — before any learning has taken place — the chance of a rat's 

 returning on emergency from a blind alley is about one to one. 

 There may be a greater tendency to go forward, keeping the 

 general orientation rather than to return; if so, the excess for- 

 ward tendency is but slight. The returns from cul de sacs first 

 to be passed seem slightly to exceed in percentage those from 

 blind alleys further on toward the food box. In the B-mazes 

 the returns from cul de sac 1 (both full length and shortened) 

 are 44% of the total number of entrances; the corresponding 

 percentages for the other blind alleys in order from 2 to 10 are 

 55, 31, 32, 48, 33, 50, 34, 13, 33. These figures are taken, of 

 course, only from the records of the untrained rats, sixteen alto- 

 gether. Those most favorably situated for returns, so far as 

 the rat's keeping the general direction on emergence from the 

 blind alley is concerned, are 2 and 5. This judgment is sup- 

 ported by the data. It is not clear why the returns from 7 

 should run so high. The percentage of returns by the eight 

 untrained rats in the A-mazes are, for the 2nd to the 6th blind 

 alley, in order: 36, 33, 67, 0, and 0. The large number for 4 

 was to be expected. The greater number of returns from the 

 cul de sacs first encountered is likely due to the fact that the 

 animals had already learned something of keeping the general 

 orientation before the other blind alleys were entered. 



In the B-mazes there appears to be a slight decrease in the 

 returns of the first two trials by the trained rats as compared 

 with the untrained. This seems to be due to a sort of " transfer 

 of training." It is likely, as the writer suggested in the earlier 

 article already referred to, due to a tendency of animals with 

 experience in mazes to proceed with less whole-souled response 

 into cul de sacs. Let us suppose that as an animal enters a cul 

 de sac it also receives certain stimuli of various kinds from the 

 true path from which it departs. These stimuli may produce 

 a weak partial response, or tendency to response, which does 

 not immediately fade away. If this tendency persists until the 

 rat emerges from the cul de sac it will, of course, enhance the 

 impulse to take the true path and thus increase the probability 

 of continued forward movement. It is not inconceivable that 

 a trained animal may have developed a habit of keeping the 



