MAZE STUDIES WITH THE WHITE RAT 271 



average number of trials involved in mastering the maze was 

 30, a group error record of zero was first obtained on the 36th 

 trial, and the average number of errors made during learning 

 was 196. The corresponding values for a group of 29 rats 

 learning the same maze while stationary were 18, 22, and 144 

 respectively. Rotation thus increased these values by 50 per 

 cent. A comparison is likewise possible between two groups 

 of rats which had had previous experience upon a different 

 type of problem. Ten rats in learning a rotated maze mastered 

 it in 21.4 trials, first secured a perfect group record on the 27th 

 trial and averaged 110 errors per rat for the learning period. 

 The corresponding values for 14 rats in mastering the same 

 maze while stationary were 9.2, 17, and 58. In this case 

 rotation has doubled the difficulty of learning. The two curves 

 of learning were similar in form; rotation seems to add on the 

 average about 3 or 4 errors to each trial and this slight addition 

 towards the end operates to postpone the final mastery of the 

 maze for many trials. 



Uniform Environment. Certain groups of rats mastered the 

 maze when covered on all sides by the canvas top. Other 

 groups also mastered this maze without the top. In one case 

 the maze habit was developed in a uniform optical environment, 

 and in the other with a heterogeneous environment. A com- 

 parison of the two sets of data will thus indicate the function 

 of a heterogeneous environment in the development of a habit. 

 The heterogeneous environment aided learning. The average 

 number of trials and the average number of errors per rat for 

 a group of 29 rats in mastering an open maze were 18 and 144 

 respectively. The corresponding values for the closed maze were 

 26 and 282. These results indicate that the animals may utilize 

 data from the objective environment in mastering the maze. 



CONCLUSIONS 



Any sensori-motor act can not be regarded as an isolated 

 independent function ; the act was learned within a wider sensory 

 environment, and it never ceases to be wholly free from these 

 conditions either during or after its development. The stability 

 of the environment furthers the development of the act, and 

 conditions the regularity and accuracy of its functioning after 

 it has become automatic. These environmental conditions 



