G2 



HELEN B. HUBBERT 



for a week before the experiment began, but during feeding they 

 were strictly confined to the food box. 



Two trials per day were given each rat, and at the end of the 

 second trial the animal was allowed to eat in the food box for 

 from three to five minutes. Milk-soaked bread was used as 

 the incentive throughout. Until the animals were 45 days old 

 they were allowed to eat food in the cage for from three-quarters 



Figure 3. Schematic representation of pathway traversed by rat No. 26 on the 

 78th trial in the maze. 

 Time, 5.8 seconds. Distance 448 cm. 



of an hour to one hour after each day's run. The rats were run 

 every day and as nearly as possible at the same hour every day, 

 since it was found that rats accustomed to being run at night 

 did not react well if forced to run in the daytime. 



The problem was considered learned when the rat, for six 

 consecutive trials, went straight to the food box without stopping 

 or turning aside from the true pathway, i.e., when all excess 

 movements had been eliminated. No time limit was set, but as 

 a matter of fact it was found that most of the rats made such runs 

 in six seconds or less. The shortest perfect run was 4.2 seconds, 



