274 JOHN D. DODSON 



fered with by the scratch reflex while the subject which is only 

 slightly hungry is frequently interfered with by it; but the sub- 

 ject trained with electric shock is less frequently interfered 

 with than is the very hungry subject. This means that the 

 native tendency of flight holds the subject up to a more efficient 

 performance of the act than does the food seeking tendency. 



Disintegration. The physiological process which takes place 

 in the nervous system in the learning process is not definitely 

 known but whatever it is it may be interfered with, or there may 

 be a tearing down process taking place along with the building 

 up process. It is in this rather broad sense that the writer uses 

 the term disintegration. The factors which cause disintegration 

 may vary from a minimum to a point where the tearing down 

 process is equal to .the building up process. Subjects trained 

 with a shock of one hundred and fifty units learned less rapidly 

 than subjects trained with a shock of seventy-five units, doubtless 

 because of disintegration due to too great excitement of the situ- 

 ation. That is, the disintegrating and integrating processes 

 were more nearly equal in the former case than in the latter. 

 Subjects trained with twenty-four hours hunger would not in- 

 frequently be headed directly towards the light box when the 

 scratch reflex would predominate over the food seeking tendency 

 and the animal would stop and scratch and then go in the direc- 

 tion which it might be headed regardless of right or wrong. 

 Subjects trained with forty-eight hours of hunger were more 

 active than subjects trained with twenty-four hours of hunger 

 but learned less rapidly, probably because of the interfering effect 

 of the strong contractions of the stomach. The physiological 

 disturbance during the first 80 trials was so great that it seemed 

 that the animals would never finish with forty-eight hours of 

 hunger, but about this time the subjects seemed to adapt them- 

 selves to the condition. 



RELATION OF RATE OF LEARNING TO RETENTION 



Our results show no marked difference in the three groups 

 tested for retention in the relative values of different degrees of 

 hunger for the retention of the habit. Of the nine subjects trained 

 with forty-eight hours hunger one made a perfect retention test; of 



