51 



Even when this* took place a rat would not immediately 



respond to the noise of the opening of the door and rush 

 to the food. In the case of the maze, there was an in- 

 crease in the time of the runs and a reourrenoe of errors, 

 CONDITIONS T 



learning is dependent upon many influences, both 

 internal and external. Internal influences usually defy 

 analysis, "but the external ones can be more easily detected. 

 When a response out of the ordinary is noticed some 

 cause is looked for, Most of the external disturbances, 

 such as noises and great variations in temperature, can 

 be avoided. Tnen ideal conditions prevail irregular re- 

 sponses dimish, and, since learning is dependent upon the 

 effectiveness of every previous response, every arrangement 

 to avoid disturbances ought to be considered. 



But these external disturbances are much less impor- 

 tant for successful progress in learning than the control 

 of the stimulus which produces the responses. Especially 



