40 

 more difficuTfc*when problems are learned abreast, is 



represented by Gurves 7II.VIII and IX. The individual 

 curves of the latch-box, when one, three and five trials 

 were given with one or more problems, are represented 

 on the curves. It is evident in each case that when 

 one problem is given the curves are shorter and simpler. 

 The same thing may be said of Curve X of the maze. This 

 might be expected /her consideration is given the fact 

 that three sets of organized movements or intergrations 

 must be learned simultaneously when solving the problems. 

 SUMMARY. 

 The results obtained from all the experiments of 

 this study point to the conclusion that a trial given 

 every two days is most economical as regards the number 

 of trials. In other words, when learning is distributed 

 over several days and not accumulated in one day, the 

 total time of learning is the shortest. In all proba- 

 bility, such distribution of trials is physiologically 



