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nerves was present. After removing the almost vertical 
tentorium cerebelli, the rest of the brain was picked out piece- 
meal. The cerebellum exhibited an extreme degree of simplicity, 
such as is found only in Perameles to my knowledge among 
Mammals. With the exception of these two genera, every other 
Marsupial with which I am acquainted has a well convoluted 
cerebellum, with a distinct vermis, from which the lateral mass 
on either side is separated by a deep sulcus, in which there is a. 
white (medullated) nerve tract. In Perameles, however, the 
cerebellum consists of a curved folium, which forms an operculum, 
covering up a few rudimentary folia near the mesencephalon. 
The superior and posterior surfaces of this folium are almost 
quite smooth, only the faintest trace of two or sometimes three 
sulci being seen. The only indication of a division into vermis 
and lateral masses is the presence of two shallow furrows, but 
there is no medullary band. In Wotoryctes the cerebellum is in 
many respects like that of Perameles. It appears to consist of a 
thin vertical slab of grey matter, which fills up the narrow 
interval between the posterior surface of the cerebrum and the 
occipital plane of the skull. Between the base of this rudi- 
mentary folium and the mesencephalon there appear to be several 
rudimentary folia. In striking contrast to the simplicity of the 
cerebellum proper, there is a large, projecting, trilobular flocculus, 
both in Wotoryctes and Perameles, lodged in a deep floccular fossa, 
which extends outwards in the petrous part of the periotic 
almost to the surface of the skull. It will be noticed in the 
Marsupial series that the cerebellum proper increases in size and 
complexity (in the number and arrangement of folia) the larger 
the size of the “ pallium” (using that term in Turner’s sense 
[42]). In Motoryctes, where the “pallium” is extremely small, 
there is a corresponding simplicity of the cerebellum. 
Concerning the rest of the brain (excepting of course the cere- 
brum) nothing can be said, since the imperfect preservation and 
the injuries inflicted during extraction forbid a proper examina- 
tion. The remainder of this account will therefore deal solely 
with the cerebrum. 
After examining the superficial aspect of the brain a median 
sagittal section was made and one hemisphere dissected. The 
other hemisphere was then stained with an aqueous solution of 
anilin blue-black and imbedded in paraffin. The block was then 
cut in a series of coronal sections. Considering the state of the 
material little was expected in the way of staining. The result, 
however, far exceeded my expectations, for a considerable 
amount of histological detail was exhibited, so that in some 
sections the cells of the fascia dentata and cornu Ammonis could 
be clearly distinguished. For this satisfactory result I am deeply 
M 
