REDINTEGRATION IN ALBINO RAT— A STUDY IN RETENTION 51 



stepped on the plane and thus opened the door to the 

 food, this action may be said to have been a response 

 to the stimuH which the plane presented to the rat and 

 no more a matter of chance than the walking of the rat 

 in any other part of the inclosed area. Similarly in the 

 first few trials the solution of the problem can neither 

 be attributed to chance on the one hand nor to any estab- 

 lished integration on the other. Gradually, at approxi- 

 mately the 8th or 9th trial, response to the plane became 

 established as the stimulus to the successive integration 

 of going direct to the food box. Whether the establishment 

 of the integration — going to the plane preceded the estab- 

 lishment of the integration — coming from the plane to 

 the door of the food box can not be definitely stated. But 

 the fact is certain that these integrations as a whole com- 

 prised the first part of the learning, while the linking of 

 the two by the establishment of the integration of pushing 



The most difficult integration to acquire in the learning, 

 and likewise the redintegration of the inclined plane, is 

 that of pushing down the plane. Invariably this move- 

 ment appears to be what has been already designated 

 as the " weak link " in the chain which constitutes the 

 successive integrations of the habit. When the integrations 

 of this movement are beginning to be established, and 

 when precision of movement first appears in the pushing 

 down of the plane, it may then be observed that the learning 

 of the problem has been delayed by this difficulty of push- 

 ing down the plane. The mass of qualitative data on 

 the learning of the plane problem confirm these facts. 

 In redintegration a similar situation presents itself. All 

 responses which the problem calls forth may be exhibited 

 on the first trial of redintegration, but frequently the 

 stepping on the plane is imperfectly integrated and the 

 habit can not be perfectly exercised. And, therefore, a 

 confirmation is here found ""for the results which were 

 noted in the study of the maze, namely, dominant " error " 

 appears in the process of learning and also in redintegration. 



Dominant " error " and imperfect integration can not be 

 shown in tabulated form for the inclined plane as they 

 were shown for the maze. But Table IX, of the three 



