No. 497] NOTES AND LITERATURE 



359 



of one of the passages, of course a different combination of move- 

 ments -will be required to reach the center; a combination which 

 it will not have learned, so that confusion would result. On 

 the other hand, if the rat recognizes the correct turns, etc., by 

 sight or other extraorganic senses, then less confusion need re- 

 sult from the changes mentioned. 



The paper of Carr and Watson is an account of the behavior 

 of the rat when the alterations above mentioned are made. When 

 the trained rat is placed, not at the entrance of the maze, but in 

 one of the passages, it appears confused, wanders about, then 

 suddenly gets a "cue," and runs directly along the correct path- 

 way to the center. The authors argue that the animal gets this 

 cue through the intraorganic sensations. The rat wanders till it 

 finds that it puts forth a certain amount of effort in a certain 

 direction and then turns in a certain direction, etc. ; this com- 

 bination is familiar, so that the correct movements for the rest 

 of the course are at once "set off" by it. 



When certain passages of the maze were lengthened or short- 

 ened after the animal had learned the correct path, this caused 

 precisely such disturbances as would be expected if the kines- 

 thetic sensations are the fundamental ones. If a passage is made 

 shorter than before, the rat runs full tilt against its end, even 

 though this would appear to be "in plain sight." If a passage 

 is made longer, the rat tries to turn when it has gone the usual 

 distance ; it thus runs against the side wall. If a blind passage 

 now opens at a distance corresponding to that of a former correct 

 turn, the rat runs into the blind passage. 



After many trials in the altered maze the rat finally learns to 

 run through it as readily and correctly as before. This result 

 is reached after many experiences of running into ends, "nos- 

 ing" along side walls, trying to turn where there is no passage- 

 way, and the like. The reader is inclined to see here an excel- 

 lent opportunity for study of the transformation of cues from 

 outer sense data into kinesthetic cues. But again the authors 

 argue that the whole is purely a matter of the inner sensations. 

 If they would explain clearly just how the animal gets its kines- 

 thetic cues without aid from outer sense data; how it learns 

 without running into the end of a passage that it must put forth 

 only so much energy in a certain direction; or if they would 

 demonstrate that bumping into walls, nosing along passages, 

 and the like, gives no extraorganic sensations of any consequence, 



