2 

 practice". Apparently learning: becomes easier when 



periods of practice are distributed over several days, 

 rather than accumulated on a single day. ITo work simi- 

 lar to that of Ebbinghaus and of Pyle had been conducted 

 on animals before this study of the white rat was under- 

 taken, and the experiments embodied in these problems 

 were completed before Pyle's work appeared. 

 THE PROBLEM. 



The object of the work here reported was to deter- 

 mine whether the rat, in learning a single problem, learns 

 more economically when making one trial or three or five 

 trials per day, and also in learning two or three problems, 

 whether it is more or less economical to learn one problem 

 before beginning another, than to learn them concurrently. 

 APPARATUS. 



Three different problems, involving the latch box, 

 the maze and the inclined plane box, were used. The first 

 two were employed onco alone, and then in connection with 



