731 
in the region of the direct lesion or of the local malacy. My supposition 
that this nucleus must be regarded as the origin of this commissuro- 
medullary bundle, gains in probability by the findings in 2 cases 
(106 and 108), where this bundle was not degenerated. In 106 the 
lesion involves exclusively the superficial layers of the anterior corpus 
quadrigeminum, but leaves the nucleus of the commissure intact. In 
108 an extensive sagittal lesion in that region was found. Here from 
the surroundings of the red nucleus a strand of degenerated fibres 
can be followed in the homolateral posterior bundle, which however 
does not disappear at the level of the n. abducens, but ean be traced 
far lower down, as far as in the dorsal spinal cord. Problably we deal 
here with the homolateral tecto-spinal bundle of Progsr. 
As to the forced movements, it is remarkable, that all these four 
animals with the degeneration of the commissuro-medullary bundle 
performed circus-movements for a short period to the side of the 
lesion, whereas the animal with lesion in the corpus qudrigeminum 
anterius solely, and that with lesion of the nuc. ruber exclusively 
did not do so. 
In relation with these cases we have to mention two animals with 
extensive lesion of the cerebral hemisphere. Whereas in 127 solely 
an extensive exstirpation of the anterior pole was performed, leaving 
the thalamus opticus intact, in 186 the whole hemisphere was exstir- 
pated and also the thalamus wounded. Only in this latter animal on 
the operated side some degenerated fibres were found, of which the 
course is exactly that of our commissuro-medullary bundle. This latter 
animal showed decidedly circus-movements to the operated side during 
some days. 
From these results we conclude, in agreement with current anato- 
mical notions, that the posterior longitudinal bundle contains fascicles 
of different source and end-station. At any rate in the medial portion 
of the P. L. B.-formation 3 bundles must be distinguished, two 
ascendent and a descendent one dealing with the coordinated locomotion 
in the horizontal plane. Innermost within the medial portion of the 
P. L. B. we find the descending commissuro-medullary bundle ; next 
comes the crossed ascendent Derrers P. L. B.-bundle, then comes the 
homolateral Bronrerew-P. L. B. bundle, containing fewer fibres than the 
crossed one. The latter bundle lies entirely within Winkrer’s Fase. 
Drirers ascendens. In a next paper the physiological analysis of the rest 
of the P. L. B. formation wil! be dealt with. There are many prepara- 
tions in my collection, which tend to prove (as far as Marcui-work is 
entitled to do so), that, as is suggested by the authors, the vestibulary- 
P. L. B. fibres, as well the crossed as the homolateral ones, in the 
