24 



JOSEPH PETERSON 



Three important features of the results are to be noted. The 

 first is the rapid decrease in the proportion of the returns to 

 forward runs, on the rat's emergence from blind alleys. With 

 the exception of blind alleys 2 and 5 in the B -mazes few such 

 returns were made after the 15th trial, though the animals 

 continued to enter some of the blind alleys beyond the 75th, 

 some even beyond the 100th. These cul de sacs, noted as 



AVERAGE PER TRIAL PERIOD 



t-5 6-15 16-25 36-45 56-05 76-85 

 TRIAL PERIODS 



-105 116-125 



Figures II and III.— CE is the curve of decrease in average number of complete 

 entrances per trial to Blind Alley 1 full length, Maze IB; R indicates the 

 decrease in returns, and 2R twice the returns, from this cul de sac. C'E' R J 

 and 2R' show corresponding data for Blind Alley 1 shortened, Maze IIB. 

 Eight untrained rats in each case. 



