Behavior: Equilibration and Dizziness 47 



covers from the effects of its experience. This description 

 of the symptoms of rotation dizziness in the common mouse 

 applies equally well to the blinded and the seeing animal. 



In sharp contrast with the behavior of the common mouse 

 in the cyclostat is that of the dancer. As the cylinder begins 

 to rotate the dancer runs about as usual in circles, zigzags, 

 and figure-eights. As the speed becomes greater it naturally 

 becomes increasingly difficult for the mouse to do this, but 

 it shows neither discomfort nor fear, as does the common 

 mouse. Finally the centrifugal force becomes so great that 

 the animal is thrown against the wall of the cylinder, where 

 it remains quietly without taking the oblique position. When 

 the cyclostat is stopped suddenly, it resumes its dance move- 

 ments as if nothing unusual had occurred. It exhibits no 

 signs of dizziness, and apparently lacks the exhaustion which 

 is manifest in the case of other kinds of mice after several 

 repetitions of the experiment. The behavior of the blinded 

 dancer is very similar. 



If these statements are true, there is no reason to believe 

 that the dancer is capable of turning or rotation dizziness. 

 If it were, its daily life would be rendered very uncomfortable 

 thereby, for its whirling would constantly bring about the 

 condition of dizziness. Apparently, then, the dancer differs 

 radically from most mammals in that it lacks visual and 

 rotational dizziness. In the next chapter we shall have to 

 seek for the structural causes for these facts. 



The behavior of the blinded animal is so important in its 

 bearings upon the facts of orientation and equilibration that 

 it must be considered in connection with them. Cyon in- 

 sists that the sense of vision is of great importance to the dancer 

 in orienting and equilibrating itself. When the eyes are 

 covered with cotton wads fastened by collodion, this writer 

 states (9 p. 223) that the mice behave as do pigeons and frogs 



