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from this nucleus cerebelli medialis as well as from the nucleus 
cerebelli lateralis lying laterally from it. On these grounds alone I 
consider we are justified in speaking of genuine nuclei cerebelli 
in Reptiles. 
On account of the close net-work of fibres that is met with 
especially dorsally from these nuclei in the Weigert-Pal preparations, 
it is extremely difficult to discover with any certainty the further 
connections of the nuclei cerebelli. Nevertheless I believe I can 
can state that fibres run between the cortex cerebelli and these 
nuclei, fibres, some of which run parallel to each other, while others 
form a fine net-work. The latter may very well originate in the 
Purkinje cells, the more so as the fibres running from a dorsal 
direction to the ne. cerebelli convey the impression of being end- 
ramifications. 
Both from the dorsal-lateral side and from the dorso-medial side, 
bundles can be seen which split off to go to the nuclei. Of those 
from the medial side some can be traced to near the raphe and 
probably originate in intersecting systems. As the neurites of the 
Purkinje cells will not likely pass the median line in the cerebellum 
of the Reptiles either, these fibres will probably come from spino- 
cerebellar and octave-cerebellar tracts. 
From the neighbourhood of the vestibular nuclei in the Alligator, 
strong tracts go to the cerebellum; the fibres accumulate in thick 
bundles which run partly medially past the 4® ventricle, partly 
upwards through the ne. cerebelli. At the level of the medulla, dorso- 
lateral and dorsally from the ne. cerebelli a few fibres curve off from 
these thick bundles, with the concavity downwards, which fibres 
go to the ne. cerebelli and there scatter in rather fine end-rami- 
fications. 
Although I cannot determine the end of these side fibres with any 
certainty, I believe | may assume that these fibres go to the cells 
of the nuclei cerebellt. This would thus mean that the nuclei cere- 
belli are connected either with fibres originating in the nucleus 
vestibularis, with direct VIII root-fibres, or with collaterals of vestibulo- 
cerebellar fibres. 4 
Frontally the nuclei cerebelli border on smaller cells lying at 
the corner of the ventricle and partly above it, which I take to 
be the forerunners of the nuclei brachii conj. of the mammals 
(fig. 9). 
These cell groups which first appear on this level, are connected 
farther frontally with the central grey matter round the aquaeduct. 
