262 HARVEY CARR 



The shifts employed were 90, 180, 270 degrees. The duration 

 of exposure to the novel conditions prior to the test was varied. 

 Three groups of animals were utilized and the conditions differed 

 so that a separate description for each group is necessary. 



1. The first group consisted of six rats and both living cage 

 and the maze were uncovered. The rats were first subjected 

 to the new orientation for 15 minutes and then tested in the 

 maze. The cage was then returned to its normal orientation 

 and control tests were given on the second day. On the third 

 day the animals were tested for the effects of a 15 minute exposure 

 to a different orientation. No animal was disturbed by these 

 15 minute exposures. Exposures of 24* hours were given for 

 three orientations on successive days. All of the rats were 

 disturbed by these alterations. The average error record per 

 trial for six tests was 2.86. Errors were present, however, in 

 but 40 per cent of the trials. There was a marked individual 

 difference in susceptibility, the number of errors ranging from 

 3 to 44. The degree of the disturbance increased with successive 

 shifts, though the rats quickly adapted themselves when kept 

 in a given orientation. 



2. The cage was covered with the canvas top and then rotated. 

 The animals were tested in an uncovered maze. The group 

 consisted of forty-five rats. They were tested immediately after 

 the rotation and then for several days in succession. Three 

 successive shifts were made before the cage was returned to its 

 normal orientation. But seven 6f the rats manifested signs of 

 disturbance and the effect was slight and quickly eliminated. 

 With one animal the effects were sufficiently obvious that a 

 disturbance can hardly be doubted. The effect was present 

 for the first day's test for two positions. 



3. In this experiment the uncovered cage was rotated, and 

 the animals were tested in a covered maze. The animals were 

 subjected to one or more day's exposure to each new orientation 

 before being tested. Seventeen animals were employed, and 

 signs of disturbance were noted for but five. The effect was so 

 slight in four cases that one cannot be confident of the results. 

 The disturbing effect was obvious for one rat for two of the 

 new positions. 



