715 
the calorie nystagmus, with various positions of the head in space, 
tonic reflexes of the eye-muscles may occur: the so-called compen- 
satory eye-positions, which alter the position of the eye in the orbita. 
Therefore, it must be ascertained beforehand whether or no the 
spontaneous nystagmus occurring after unilateral extirpation of the 
labyrinth, alters its direction with different positions of the bead in space. 
Such experiments have been carried out, for aught we know, 
only by Kuso‘). They will be briefly discussed here: Kuso severed 
one octavus. He does not tell us how he did it, nor whether he tried 
to ascertain by a subsequent control section if the process was 
successful. It would seem from the protocols that this is highly 
doubtful. Six of the experiments are reported in detail, of which a 
short description follows here: 
Experiment 1, +, and 5 will not receive consideration, because in 
them the nystagmus was not examined with different positions of 
the head. 
Experiment 2. 
In this experiment a nystagmus appeared with the quick component 
towards the operated side, after section of the right octavus had 
been performed. The nystagmus consequent on unilateral extirpation 
of the labyrinth, however, turns towards the unimpaired ear. Kuso 
adds only: “Diese Bewegungen bleiben unverändert, wenn man die 
Körperlage des Tieres ändert.” 
Experiment 3. 
Left acusticus cut through. Subsequent vertical nystagmus-move- 
ments. After a couple of hours perfectly horizontal nystagmus witb 
the quick component on the operated side towards the nose. Just 
as with the vertical nystagmus this direction is the same for any 
position of the animal. A flow of cold water into the right meatus 
is of no influence. After the semi-circular canal of the right ear has 
been laid bare, the experimenter states: ‘Nach Hinspritzen von 
kaltem Wasser ändert sich die Richtung und es tritt eine rückweise 
Bewegung nach der Nase hin auf der operierten (linken) Seite auf.” 
This, however, was also the existing direction and opposite to the 
one we can look for in the case of cold-water nystagmus from the 
right ear. The vertical nystagmus also points to an imperfect section. 
Experiment 6. 
Section of left acusticus. First vertical, afterwards horizontal 
nystagmus (on the left with the quick component towards the nose.) 
1) Kuso Iso. Ueber die vom N. acuslicus ausgelösten Augenbewegungen (besonders 
bei thermalen Reizungen.) Pflüúg. Arch. 114. (1906) S. 143. 167. 
47* 
