34 



THOMAS WILLIAM BROCKBANK 



TABLE V-B 



30-Day Period. 1 Trial per Day 



Time in Seconds 



Averages — 

 Trials... L 76.5 

 R. 22.1 



* (Perfect) Trials.. L. 12.7 

 R. 10.2 



Time..L. 16.9 

 R. 19. 



has already been proven concerning dominant " error," 

 but will be used as a norm for comparison with a second 

 group, at 30-day retention, which will be taken up now. 



(6) Influence of Learning a New Problem during the 

 Retention Period 



This group was undertaken with the view of obtaining 

 some light in regard to the effect of the acquirement of a 

 new habit on the retention and redintegration of a habit 

 already acquired. The group comprised two litters, the 

 first of three rats, 1, 2, and 3, respectively, and the second 

 of seven rats, 4, 5, 6, 7, 8, 9, and 10, respectively, in Tables 

 VI-A and VI-B. Rat 3 of litter 1 failed to complete 

 redintegration, while rat 10 of litter 2 died before com- 

 pleting retention. Each litter was set to learn the maze 

 by the one trial per day method. The object of the present 

 problem required that at the beginning of the retention 

 period, instead of following the method of exercise in the 

 runway during retention, each rat was to begin the learning 

 of a new problem. This new problem was the " rope- 

 ladder " problem. As the name suggests, it was constructed 

 of first, a rope about 1 cm. in thickness and 93 cm. in 



