198 T/ie Dancing Mouse 



organs of the body furnish the dancer with impressions which 

 serve as guides to action and facilitate habit formation, 

 although they are not necessary for habit performance. 



The reader may wonder why I have not carried out sys- 

 tematic experiments to determine accurately and quantita- 

 tively the part which each sense plays in the formation of a 

 labyrinth habit instead of basing my inferences upon inci- 

 dental observation of the behavior of the dancers. The 

 reason is simply this : the number and variety of experiments 

 which were suggested by the several directions in which this 

 investigation developed rendered the performance of all of 

 them impossible. I have chosen to devote my time to other 

 lines of experimentation because a very thorough study of 

 the conditions of habit formation has recently been made 

 by Doctor Watson. 1 



What is the role of sight in the dancing mouse? How 

 shall we answer the question ? The evidence which has been 

 obtained in the course of my study of the animal indicates 

 that brightness vision is fairly acute, that color vision is poor, 

 that although form is not clearly perceived, movement is 

 readily perceived. My observations under natural conditions 

 justify the conclusion that sight is not of very great impor- 

 tance in the daily life of the dancer, and my observations 

 under experimental conditions strongly suggest the further 

 conclusion that movement and changes in brightness are the 

 only visual conditions which to any considerable extent con- 

 trol the activity of the animal. 



1 Watson, J. B., Psychological Review, Monograph Supplement, Vol. 8, No. 2, 

 1907. 



