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J. F. DASHIELL 



answer has been suggested above but not definitely shown in 

 terms of data. In this series the general description of the pro- 

 cedure of the experiments can be much abbreviated. 



The ages and grouping of the rats are shown in table 4. 



All groups were first given opportunity to learn to push open 

 the door of the food box when placed on a table. Group I had 

 this practice only before its formal maze trials. It was given this 

 seven times. 



TABLE 4 



TABLE 5 



Group II was given the run through the single passage NA 

 (fig. 1) for ten trials. Time was this time taken. The group 

 as a whole showed a fairly regular decrease of time as given in 

 table 5. 



Group III in twenty-five trials or less in maze PA performed 

 almost exactly as did the group III of the earlier series, showing 

 a learning of so similar a type that space need not be given to 

 its scoring. 



Group IV in twenty-five trials in the changing mazes CA gave 

 results showing graphicaUy in figure 9. In comparison with 

 figure 5 we find here the same very general downward trend 



