44 The Dancing Mouse 



mouse, is, in general, very complete. The seeming reduction 

 which appears under certain conditions should be attributed, 

 not to visual dizziness, but in part to excitability and rest- 

 lessness, and in part to a reduced muscular power" (31 p. 161). 



FIGURE 5. Tracks of common mouse. Reproduced from Alexander 

 and Kreidl's figure in Pfliiger's Archiv , Bd. 82. 



The dancer certainly has far less grasping power than the 

 common mouse, and is therefore at a disadvantage in moving 

 about on sloping surfaces. One evidence of this fact is the 

 character of the tracks made by the animal. Instead of 

 raising its feet from the substratum and placing them neatly, 

 as does the common mouse (Figure 5), it tends to shuffle along, 



FIGURE 6. Tracks of dancing mouse. Reproduced from Alexander 

 and Kreidl's figure in Pfluger's Archiv. Bd. 82. 



dragging its toes and thus producing on smoked paper such 

 tracks as are seen in Figure 6. From my own observations 

 I am confident that these figures exaggerate the differences. 

 My dancers, unless they were greatly excited or moving under 

 conditions of stress, never dragged their toes as much as is 

 indicated in Figure 6. However, there can be no doubt that 

 they possess less power of grasping with their toes than do 

 common mice. The animal is still further incapacitated 



