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rotatory movements and reactions upon progressive movements), 
while all tonic labyrinth reflexes of the position are lacking. 
2. If these animals be kept alive for some days, and examined 
every day as to their labyrinth reflexes, it can be seen that in some 
animals this condition remains unaltered, while in others the tonic 
labyrinth reflexes return partially or even wholly. 
3. A histologicai examination of one animal, where a complete 
recovery had taken place, showed that all the otolithes were in 
place with the exception of one utriculus otolith, which appeared 
to be injured. This last, however, was in entire accordance with 
the phenomena found clinically. The apparatus of the semi-circular 
canals was likewise intact. 
4. In one guinea-pig which, after two days, showed intact labyrinth 
reactions upon movement (reactions and after-reactions upon rotatory 
movements and reactions upon progressive movement), but, on the 
other hand, no tonie labyrinth reflexes, all four otolithes were found, 
upon histological examination, to be torn off, and were found in 
Other places iu the labyrinth, while the canals with the cristae 
appeared to be intact. 
It follows from the above data that: 
5. The labyrinth reflexes on movement, and in particular the 
reactions and after-reactions of head and eyes on rotatory movements, 
are reflexes of the semi-circular canals, and may be excited even 
when the otholithes are lacking. 
6. The same holds good for reactions upon progressive movements. 
7. On the other hand, the tonic labyrinth reflexes (tonic labyrinth 
reflexes upon the muscles of the body, ‘“abyrinthstell-reflexe” and 
compensatory positions. of the eyeball) are otolith-reflexes, which 
cannot be produced after the destruction of the otolith membranes. 
8. In many cases, directly after the centrifugation, the function 
of the otolithes is temporarily suspended owing to the strong mechanical 
influences upon the specifical heavier otolith membranes, even 
though the otolith membranes themselves still lie in their right places. 
The function is only restored after various lengths of time. 
9. It thus appears from these and previous data, that the reflexes 
upon movement (reactions and after-reactions of head and eyes upon 
rotatory movements and the reactions on progressive movements) are 
excited by the semi-circular canals, while the otolith apparatus must 
be held responsible for the tonic labyrinth reflexes (tonic labyrinth 
reflexes on the muscles of the body, ‘Labyrinthstellreflexe” and 
compensatory positions of the eyeball). 
„10. This naturally does not exclude that the otolith apparatus 
