730 
manege-movement was noted to the side where the P. L. B. shows 
the least degeneration (the lesion being on the same or on the other 
side). Some reserve I have to make here for the homo-lateral dege- 
neration in the longitudinal bundle after lesion of BecaTerEw’s nucleus. 
For in 95, being the animal, that produced the most classical circus- 
movements-to the left, a very local lesion was found in the middle 
part of the ingoing fascicles of the N. vestibularis. It can a priori 
not be excluded, that such a direct and local lesion of the nerve may 
cause manege-movement to the other side, in the same way as usually 
any lesion of the vestibulary nerve causes vehement and long lasting 
rolling movements to side of the lesion’). Such an interpretation seems 
however very improbable indeed. As to 111, the lesion was here 
accompanied by an haemorrhage and rather extensive. The physio- 
logical analysis of the Deirers-complex can go, I think, a little further, 
in that a lesion of the caudal part of the complex, e.g. on the right 
side, as well as a lesion of the proximo-dorsal part (BECHTEREW’s 
nucleus) of the left side resulted in an ascendent degeneration in the 
P. L. B., of the left side, and also produced equally circusmove- 
inents to the right. This circus movement to the right side being 
elicited from an anatomical entity on either side, we are led to believe, 
that a double sided connexion of either horizontal semicircular canal 
with Derrers nucleus and a proper extension of EwaLps experiments 
might clear up this point. 
From these results I think it must be admitted, that the physio- 
logical function of the P. L. B., or at least one of its functions, is 
intimately related to the coordinated locomotion in the horizontal plane 
of eyes, head, trunk and extremities. A similar suggestion of such a 
relation is often found in literature, but about the precise form and 
direction resulting from such coordination none of these researches 
give information (EDINGER) *). 
-In a fourth group of experiments (in 6 animals) a lesion was applied 
in the region of the corpora quadrigemina anteriora, of the commissura 
posterior and of the red nuclei. In four cases descending degeneration 
from that region into the posterior longitudiual bundle, exclusively 
on the side of lesion, was found. This degeneration, sometimes amount- 
ing to no more than a few fibres, is lost sight of high in the medulla 
oblongata, especially in the region of the abducens-nuclei. In 2 of 
these cases accurately the origin can be followed in the series and 
it appears that the nucleus of the posterior commissure is involved 
1) Compare: Studies on the forced movements. Journal of Physiology. XXXI. 
Ne. 3 and 4. 1904. 
2) Vorlesungen. 1912, P. 110. 
