188 STUDIES IN GENERAL PHYSIOLOGY 
its eyes are rotated more or less about the long axis of the 
body toward the left, so that the left eye looks downward, 
while the right eye looks upward. The (persistent) geo- 
tropic movements of the eyeballs upon changing the orienta- 
tion of the animal toward the center of the earth still occur, 
with this modification, however, that when the whole animal 
is turned about its longitudinal axis the amount of the com- 
pensatory movement of the eyes is added algebraically to 
that caused by the lesion of the ear. 
4. Only a slight change is noticeable, usually, in the posi- 
tion in which the pectoral fins are kept. The left lateral 
fin is turned toward the back while the right is turned 
toward the abdomen. 
Il. If the otoliths of such an animal are removed from 
the other side also, all the phenomena described above dis- 
appear. Instead, however, now the following abnormalities 
appear: 
1. The animal is no longer compelled to turn its ventral 
side toward the center of the earth. If one carefully attempts 
to lay it upon its back the animal does not resist, and when 
prevented from falling over, it remains permanently upon its 
back. When left to itself, the animal is often found lying 
upon its back, or swimming in this position, even when it is 
entirely well and vigorous. 
2. The permanent alterations in the position of the eye- 
balls, when the orientation of the animal toward the center 
of the earth is changed, are lacking. 
ITI. If the antrum is opened and the same injuries are 
inflicted as are necessary to remove the otoliths—without, 
however, injuring these or the nerves of the antrum—the 
phenomena described under I and II do not appear. Nor is 
this the case when large pieces are removed from the semi- 
circular canals without injuring the ampulle. 
IV. If the left auditory nerve of the animal is cut, the 
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