1358 
phase must be looked for in the periphery. By stimulating the 
labyrinth certain eye-muscles gradually contract and their antagonists 
relax simultaneously (slow phase). This process is supposed to elicit 
a reflex which causes a rapid contraction of the originally relaxed 
eye-museles and a rapid relaxation of the originally contracted eye- 
muscles (quick phase). He relinquished his primary view that, owing 
to the contractions of the eye-museles, the terminal branches of the 
trigeminus are stimulated and the reflex for the quick phase has its 
origin here, and adopted the view that the proprioceptive nerve- 
ends in the eye-muscles themselves, demonstrated experimentally by 
Tozer and SHERRINGTON '), represent the beginning of the reflex arc 
for the quick phase of the nystagmus. 
Now it seems easy at first sight to test experimentally the validity 
of Bartris’ conception. When isolating one of the eye-muscles and 
recording during a nystagmus the movements of this muscle accord- 
ing to Barrers’ method on a Kymograph we need only to paralyse 
the proprioceptive nerve-ends in this muscle and see whether the 
rapid phase disappears. 
Bartets’) himself had tried this previously by injecting cocain 
into one of the orbitae. This however engendered such a rapid 
paralysis of all the eye-nerves that the problem could evidently 
not be solved in this way. 
However we now possess a means to paralyse the proprioceptive 
nerve-ends in the muscle. LirJESTRAND and Maenus’*) have demonstrated 
that after injections of certain doses of novocain the muscles at the 
place where the nerves enter, the proprioceptive nerves are paralysed 
while the motor nerves retain their functions. 
If it should appear, however, that in these experiments the rapid 
phase does not become extinct (or would with larger doses disappear 
only simultaneously with the slow phase at the moment when the 
entire eye-nerve has been paralysed) this could not be put forward 
as an argument against the theory of BARTELS. 
When a nystagmus occurs, contractions and relaxations of various 
muscles of both eyes take place. If, therefore, one wishes to paralyse 
the proprioceptive nerve fibers, which come into play for the reflex 
of the rapid phase, it is not enough to inject novocain into the 
isolated muscle, but one has to eliminate all proprioceptive fibers 
of all eye-muscles. 
1) Folia Neurobiologica. IV, p. 626. 
*) Klin. Monatsblätter für Augenheilkunde 1914. Bd. LIII, p. 365. 
3) Pflügers Archiv. Bd. 176, p. 168. 
