Physiology. — “Concerning Vestibular Eye-rejleves. 11. The Genesis 
of cold-water nystagmus in rabbits’: By Dr. A. pe Kuryn and 
Dr. W. Storm van LEEUWEN. (Communicated by Prof. R. Magnus). 
(Communicated at the meeting of January 31, 1920). 
For an explanation of cold-water nystagmus we may have recourse 
to two theories. Barany’s theory is founded on the assumption of 
a stream of endolymph in one or more semicircular canals, brought 
about by local cooling of the labyrinthwall. This will cause also the 
endolymph, present there, to cool down and to flow off to the 
lowermost part of the semicircular canal. The ensuing lymph stream 
stimulates the sensory epithelium of the ampulla. In case the head 
of the animal is in a position in which the ampulla lies higher 
than the cooled part of the semicircular canal, the stream will be 
ampullofugal; if the reverse be the case an ampullopetal stream 
will result. The nystagmus elicited by each stream is of an opposite 
character. 
Bartets holds that by douching of the meatus with cold water 
the labyrinth would be eliminated, so that the nystagmus provoked 
would be like the spontaneous nystagmus after unilateral extirpation 
of the labyrinth. A warm water flow would be like stimulation of 
the N. vestibularis on the same side. 
In a previous paper, issued from this institute, we have disproved 
BARTELS’s theory’). 
Moreover, it has already been contended by many other researchers. 
lt was first of all pointed out that, if Barreis’s conception were 
correct, a cold-water nystagmus could not possibly be elicited from 
the unimpaired ear after unilateral extirpation of the labyrinth. 
Hover?) has phrased it so well: “dieses tatsächliche Auftreten eines 
rotatorischen Nystagmus nach der operierten Seite ware nach Barrnus’ 
1) A. pe Kiewsn and W. Storm van Leeuwen. Ueber vestibuläre Augenreflexe I. 
Ueber die Entstehungsursache des kalorischen Nystagmus, nach Versuchen an 
Katzen und Kaninchen, Graefe’s Arch. 5 Bd. 94 316, 1917. 
A. pe Krog and W. Srorm van Leeuwen. Over vestibulaire oogreflexen 
| Mededeeling. Kon. Acad. van Wetensch., Amsterdam. Wis- en Nat. Afd. Versl. 
Deel XXVI, 381, 1917. 
4) J. Hover. Untersuchungen über den calorischen Kaltwassernystagmus. 
Monatsehr. f. Ohrenheilk. (1912) S. 1313. 
47 
Proceedings Royal Acad. Amsterdam. Vol. XXII. 
