6 THOMAS WILLIAM BROCKBANK 



lem was fed every day for 30 minutes in the center of the 

 maze, the entrance to which had been temporarily closed. 

 The object of this procedure was to allow the rat, first, to 

 adjust itself to the new environment, and, second, to ac- 

 quire a certain association between this experimental en- 

 vironment and its daily food. On the first day of learning 

 a bowl of bread and milk was placed in the center, and 

 a rat of the group was placed by hand in the entrance 

 box. The rat was permitted to emerge into the first alley 

 of the maze, immediately after which the door was closed 

 behind it and a stop watch started. The graphic record 

 was also begun at this time and the course of the rat traced 

 until the center was reached or a failure was recorded at 

 the end of 30 minutes. Each rat of the group was ex- 

 perimented with in turn. The first day's experiment was 

 completed for the one trial per day group at the end of 

 the first trial. 



With the three trials per day rats, the rat on reaching the 

 center was immediately replaced in the entrance box for a 

 new trial, and the previous procedure was repeated as also 

 in the third trial. When the experiment for the day had 

 been completed the group was fed in its respective cage 

 on bread and milk, and a small ration of grain; no more 

 food was allowed until the next day. Miss Hubbert (21) 

 has stated that ill effects may arise from this method of 

 feeding. In the present work this method was employed 

 throughout all experiments and nothing detrimental was 

 detected. 



In this research the method of learning and its norm were 

 important, inasmuch as both were to be applied in the 

 series of trials after the retention period. No time norm 

 was adhered to rigidly. Six seconds is usually considered 

 the time norm for this maze, but rats were frequently 

 found that ran the maze perfectly, although in somewhat 

 slower time. The norm for learning, therefore, covered a 

 period of the last fifteen trials, the first six trials of which 

 were required to show perfect integration of all movements, 

 and at the same time such speed as would indicate the 

 establishment of the integrations. Less than fifteen trials, 

 the first six of which are perfection, can not be called a norm. 



