30 



movements were made, unless the act was performed within the 

 limits of the time set, it was not considered perfect. For 

 the purposes of this experiment si<ch a norm was not desirable, 

 since one of the i oints under investip:ation was tiie relative 

 final rate of efficiency attained by rats of different ages. 

 Klimination of all useless movements for three days was there- 

 fore considered as sufficient evidence that the problem had 

 been learned. The number of trials required to reach this 

 level of efficiency varied with each rat, the extreme limits 

 being fourteen, and one hundred tv;elve trials. Ln a single 

 trial any distance greater than 4.5 meters, which is the length 

 of the errorless pathway from the entrance to the food, rej - 

 resents excess effort on the part of the animal. 



If a rat remained in the maze for fifteen minutes v/ith- 

 out reaching the food box he was taken out and replaced in the 

 entrance box for a second attempt. Distance and time were re- 

 corded in the same way as for a successful run, i.e., if the 

 first effort to reach the food proved unavailing after fifteen 

 minutes, and the second attempt was successful after eight 

 minutes, the total time for the first trial v.ould be twenty- 

 three minutes and the total distance the combined distance of the two 

 attempts. Should the rat fail on the second effort also, it 

 was fed for three minutes in the maze with the food box jarti- 

 tioned off as for preliminary feeding, and tried again the fol- 

 lowing day. 



The time and distance records for each trip were careful- 

 ly tabulated, and form the basis for the conclusions which ap- 



