30 'Journal of Comparative Neurology and Psychology. 



basis of an average of eighteen trials for each animal. This 

 would imply that under these conditions, three trials per rat were 

 required by it in order to learn to start at random from any one 

 of six cul-de-sacs. A greater number of trials, however, is neces- 

 sary when the animal is forced to start at random from six such 

 positions in the true pathway. In the latter case, orientation at 

 these positions does not become immediate in less than five or 

 six trials."^ 



With these facts bearing upon the behavior during the establish- 

 ment of orientation before us, we may now well ask the question: 

 how does the rat attain orientation .^ Can he do it in terms of 

 kinaesthetic data alone .^ From our previous work upon the behav- 

 ior of normal, blind, and anosmic rats in tests of this kind in the 

 Hampton Court maze, it appeared, since no difference in conduct 

 between the normal and defective animals could be found with 

 respect to their ability to attain orientation when put down in the 

 maze at unfamiliar starting points, that visual and olfactory data 

 are at least not largely employed by them as a means of controlling 

 their movements. This conclusion is based upon the assumption 

 that the processes employed as control by the defective rats are the 

 same as those which would have been employed by them had they 

 been normal. Let us suppose, for example, that a normal rat 

 does use visual data, or the data from some other "distance^' 

 sense, for controlling his movements when the automatic (kin- 

 aesthetic-motor) character of the act is interfered with, as is the 

 case at first when the animal is started in the maze at some point 

 other than the customary one. What would be the nature of the 

 orienting process .'' Evidently the animal would have to move at 

 random until distinctive familiar visual or other extraorganic 

 stimulation appeared, at which time the automatic series would be 

 restored and the animal might thereafter have no further need 

 for distance sense data during the remainder of the trip around 

 the maze. 



If, however, we deny to the rat the possibility (or better, the 

 probability) of its using distance sense data in the way described 

 above, it becomes necessary for us to answer the question: how 

 can a kinaesthetic-motor series, which has been thrown out of gear 

 become readjusted without control data from some other sense 

 avenue ^ 



Summarized from Carr's unpublished results. 



