1429 
a few cells which, according to Herrick, are apparently reduced 
Purkinje cells. 
Fibrae arcuatae internae proceed from the entire extent of the 
area acustico-lateralis; one portion crosses the raphe, another portion 
descends on the same side. 
Of the caudal portion of the cerebellum similar fibrae arcuatae 
go off; some of them go to the tegmentum, some to the formatio 
reticularis. Some of these fibrae areuatae now — both of the 
cerebellum and of the lobus anterior of the area arcustico-lateralis — 
pass frontally into the mesencephalon. These bundles form the 
brachium conjunctivum. As far as the cerebellum is concerned, they 
all come from the eminentia ventralis, none from the dorsal portion 
of the cerebellum. Thus in many respects there is great similarity 
with the conditions which I have described in Selachians. HerRICK’s 
preparations, however, enabled him to arrive at a more definite 
conclusion. He was able in some preparations to trace the neurites 
of the cells from the eminentia ventralis cerebelli into the brachium 
conjunetivium. Since in mammals the brachium conjunctivium rises 
in the’ nucleus dentatus and nucleus teeti cerebelli, Herrick, on ac- 
count of these facts, very rightly considers the cells of the eminentia 
ventralis cerebelli as the primordium of the nucleus tecti and nucleus 
dentatus. 
Reptiles. 
Of the nuclei cerebelli of the Reptiles but little is known. Bancut'), 
who admits a nucleus dentatus in Amphibians, denies this in the 
case of Reptiles. EpINGER®) mentions that as in bony-fish, sharks 
and Amphibians, so also in Reptiles a small group of cells occurs 
laterally in the cerebellum, that these little cell-groups will probably 
be homologous with the nucleus dentatus of mammals, but that too 
little is known as yet regarding the connections to be able to say 
anything about them with certainty. Regarding the medial nucleus 
(nucleus tecti) he says emphatically that they do not oecur in animals 
lower than birds, exeept in Chelone nidas, a turtle. 
In a crocodile, Aligator sklerops, | found distinct cerebellar 
nuelei, which I reproduce here in Figs. 6 to 9. We recognise here 
two groups of cells, a medial group of in general darker cells, 
which may well be called nucleus cerebelli medialis, and the cells 
1) BancHt: Sulle vie di connessione del cervelletto. Archivio di Anatomia e di 
Embriologia. Vol. IL. Fase 2. 1905. 
2) EpinGer: Bau der nervösen Zentralorgane IL Bd. 1908. 
