243 
the question (reflexes of the neck). The various positions of the 
eyes were determined kinematographically. Minute measuring was 
made possible by indicating on the photographic plates the shifting of 
a cross, burned into the cornea anaesthetized by cocain, with regard 
to a fixed system of coordinates, photographed at the same time. 
The results were indicated for the vertical deviations of the eye 
and for the rotatory movements separately, to wit for three per- 
pendicular rotations of the head round 360° each. 
In this way we only get to know, of course, the influence of 
the head, i.e. the labyrinths on the position of the eyes. However, 
for a minute analysis of the influences of the labyrinths it is desirable 
to know the influence of the labyrinths on each eye-muscle. 
Now, as different positions of the head often bring about a com- 
bination of vertical deviations of the eye and rotation movements, 
which combination, in its turn, variously modifies the points of 
insertion of the eye-muscles, it stands to reason that we cannot say 
beforehand that the greatest deviation of the eye-ball either upwards 
or downwards, or the full extent of any of its rotations, necessarily 
implies the maximum lengthening or shortening of the eye-muscles 
(recti and obliqui). This made it necessary to investigate what 
position of the head produced the maximum and minimum shortening 
of the eye-muscles. The above-mentioned inquiry had clearly brought 
out in what way each position of the head influences the position 
of the eyes, so that the only thing left fo be done now, was 
construction of a proper model of an eye, putting the eye-ball 
of this model in the various positions which had been fonnd, and 
measuring the length of the six eye-muscles for each position 
accurately. 
A short time ago the anatomical relations of the eye-muscles of 
rabbits were given in detail by Wesserry '). However the accom- 
panying illustrations do not give us the numbers expressing those 
relations. 
For this reason a minute inquiry was made with various rabbits 
with regard to the length of the eye-muscles, size of the eye-ball, 
place of insertion for each muscle, etc. and in accordance with this 
the instrument-maker of the Institute, Mr. F. A. C. Imnor, made a 
model of an eye-ball with eye muscles to correspond. 
Starting from the primary position of the eyes and guided by the 
information obtained before with regard to rotatory movements and 
vertical deviations of the eye for different positions of the head, now 
1) K. Wessety. Ueber den Einflus der Augenbewegungen auf den Augendruck. 
Arch. f. Augenheilkunde. 81. 111. 1916. 
