628 



ering, however, that we only endeavoured to ascertain whether 

 or no with bilateral irrigation a rotatory movement occurred, this 

 did not matter at all. So when the two photographs had been taken 

 prior to the irrigation, a simultaneous flow of cold water into both 

 meatus of the animal was performed, and when no nystagmus was 

 distinguishable any more, again two phothographs were taken of 

 the head, in two positions. A measurement of the rotatory move- 

 ment, caused by the change of position could now be made on the 

 photographs. The difference between the movements in the two 

 positions (head down and head up) amounted to 



Exp. Without irrigation after bilateral irrigation 



1 66,5° 57° 



2 70° 65° 



3 59° 61° 



4 88° 98° 



5 63° 78° 



From this table it is obvious, then, that after a flow of cold water 

 into the two meatus of rabbits a strong rotatory movement is still 

 effected by a change of the animal's position m space, perhaps as 

 strong as with normal animals. 



For the present we refrain from theoretical speculations on the 

 basis of these experiments. Our object in publishing onr experience 

 was only to prove that the caloric nystagmus cannot possibly be 

 provoked by a complete elimination of the labyrinth by cold water. 



