106 

 successful, he v'as taken out wliile tlie door was oi)ened, and 

 he wag then returned to feed for five minutes and used no more 

 that day. V.lien they bej^an to succeed within the half }iour, 

 each rat was required to open and enter the food box five tinieo 

 each day. At the end of the fifth trial it was allowed to feed 

 for five iriinutes, but pei-nitted no nore food until the conple- 

 tion of the next day's experiment. Fach tat was used daily 

 foi- tv/enty days. As a tine limit had been placed, no criterjon 

 of perfect learning v/as establiphed for this experiment. At 

 the conclusion of the learnint: experiment the rats v^iere fed 

 in the runway which has already been described for sixty days. 

 At the end of this period they v;ere tested for retention, and 

 were worked for five days in order to asoertfin the effects 

 of the previous training. 



The results of the experiment for the inbred rats 

 are given in tables Via, VIb , and Vic; for the normal control 

 series in tables Vila, Vllb, and VIIc. These tables ^iye only 

 the averages of the five daily trials of individual rats. Ta- 

 bles Via and Vila show, respectively, the daily averat:e time 

 in seconds of the inbred and normal control series during the 

 process of forming the inclined plane habit. The time includ- 

 es both opening the door at the plane and entering the food 

 c ox . 



Tables VIb and Vllb show the absolute retention of 

 the inbred and normal control series respectively. These ta- 

 bles show the absolute retention of the normal control series 

 to be stronger than than that of the inbrnd. 



Tables VIc and VIIc serve only to show individual 

 daily averages during the five days of testing for tiie effects 

 of previous training. The inoividuril anatomical data, can with 

 the above be better treatea in the comparative summariefl. 



