x 
George L. Streeter 307 
In the region of fig. 6 we observe adjoining the median line on each 
side the nucleus funiculi teretis, overlapped by the obliquely cut fibres 
of the striae medullares. In some of the sections studied, to all appear- 
ances many of the fibre bundles of the striae ramified in the nucleus, and 
seemed to terminate there. It is realized, however, that such histo- 
logical pictures may be very misleading. It is considered to be far from 
conclusive evidence regarding the relation between the two structures. 
The distal and proximal ends of the nucleus are indicated in Plate II. 
It will be observed that the nucleus corresponds in its position very 
closely to the area of the striae. It is distinctly separated from the 
eminentia teres. 
There is a large field of grey matter, in fig. 6, bounded by the nucleus 
funiculi teretis mesially, the descending bundles of the vestibularis 
laterally, and ventrally by the formatio reticularis and the fasciculus 
solitarius with its nucleus. Concerning the signification of this field 
there is at present a divided opinion. The majority of writers con- 
sider the entire space to belong to the dorsal vestibular nucleus. 
There are others, however, who consider the median part of this field 
to belong to the nucleus of the glosso-pharyngeus. By going through 
a series it is easy to see that the median part of this field is a con- 
tinuation of what Staderini and Van Gehuchten in more caudal sec- 
tions call the nucleus intercalatus. The area occupied by this nucleus is 
indicated on Plate II as Nucleus intercalatus. In the region of fig. 6 
this nucleus seems to fuse with the dorsal vestibular nucleus, and in 
myelin sheath and Nissl preparations the two areas have the same struc- 
ture and no dividing line can be made out. That they, however, are 
not the same, but, on the contrary, have different functions is supported 
by the following reasons: 
Firstly. If the nucleus intercalatus belonged to the vestibular nucleus 
the area occupied by the two would be greater than that occupied by 
the combined nuclei of the glossopharyngeus, vagus and hypoglossus. 
This would be out of all proportion to the function of the vestibular 
nerve, as we at present understand it. Secondly. In many human speci- 
mens where the striae are absent or only faintly marked, and even 
better in other mammalians (calf and sheep), the naked eye appearance 
of the floor shows the vestibular nucleus to be separated from the nucleus 
intercalatus by the lateral furrow which connects the superior and 
inferior foveae. Thirdly. We have already seen that in neuroglia fibre 
specimens, processes extend from the ependyma ventrally into the grey 
matter forming partitions between the dorsal nuclei. In specimens 
of this region prepared in that manner there exists a neuroglia parti- 
