EFFECT OF LENGTH OF BLIND ALLEYS ON ^L\ZE LEARNING 23 



returns and eight cases of the animal keeping its general forward 

 orientation; and so on, through the results for all the blind 

 alleys in order. 



Note that the figures for groups 'Mii and St are in bold face 

 for blind alley 1, and not for 2, and that these relations are just 

 reversed for the groups of animals running in Maze I IB. The 

 bold face designates full length cul de sacs, and the figures not in 

 bold face indicate that the blind alley was shortened. The amount 

 of shortening in any case is shown in figure I, as already explained. 

 Careful attention to all these matters will greatly aid the reader 

 in getting quickly and conveniently the general results of 

 numerous reactions. Without such attention the tables are 

 meaningless. The results cannot so well be effectively and 

 accurately shown in graphs. 



The totals at the foot of the columns must not be taken too 

 seriously, as will be evident in subsequent discussion. These 

 are totals only of changing comparative quantities. For this 

 reason the results of the experiments have been classified for 

 different periods of the training. The results of the first two 

 trials are given separately — and are not added in the totals 

 because they are again included in the data for the 1st to 5th 

 trials — as they are least affected by the animals progressive 

 training. They show us approximately whether mere chance, 

 or probabilit}^ laws, can explain the direction that an animal 

 beginning in the maze takes on emerging from a cul de sac, 

 whether it returns or continues forward keeping its general 

 orientation, — not accurately, however, for learning begins from 

 the very first experiences in the maze. The progression of the 

 learning in the case of each particular cul de sac is shown by a 

 gradual decrease in entrances in the summaries of the 1st to 

 5th, the 6th to 15th, 16th to 25th, etc. trials; also by the gradual 

 decrease in returns and the increase, correspondingly, in the 

 number of cases of keeping the general forward orientation. 

 These two kinds of changes are very interesting and illuminating 

 toward showing, in a manner not hitherto done with data on 

 learning, just how the cul de sacs are eventuall}" eliminated. '^ 

 This is our main concern in this paper. 



" Professor Carr has pointed out that the ex'tent of entrance to cul de sacs grad- 

 ually decreases, as well as the number of entrances. (Hicks, V. C, and_Carr, H. A. 

 Human Reactions in a Maze. Jour. Animal Behav., 1912, 2, 98-125. See par- 

 ticularly page 116.) 



