NERVOUS CENTRES. (Human Anatomy. Tur ENCEPHALON.) 
seribed by Tarin and Malacarne. When the 
fourth ventricle has been carefully opened in a 
recent cerebellum, it is very easy to demon- 
Strate them by passing the handle of a knife 
under them. 
The structure of these lateral wings of the 
inferior medullary velum is readily ascertained. 
Their delicacy is such that they admit of being 
examined by the microscope without pressure 
or other manipulation. They consist of tubular 
fibres of various sizes, taking a transverse di- 
rection, that, namely, of the long diameter of 
each wing, covered by a layer of nucleus-like 
particles as an epithelium. They seem to con- 
nect the nodule to the small lobules of the 
neumo-gastric nerve above mentioned (the 
Jtocks of Reil), or to connect those lobules them- 
selves as a commissure.* 
The nodule pushes before it, into the fourth 
ventricle, a fold of the pia mater, connected 
_ with which on either side are several small 
granulations, or Pacchionian bodies. It is called 
_ the choroid plexus of the fourth ventricle. We 
_ ¢an easily trace it to be continuous with the pia 
mater which covers the lobules of the seventh 
_ pair of nerves. 
Next to the nodule, below and behind it, is a 
_ small lobe, called by Reil the spigot ( Zapfen ), 
with a pointed extremity directed downwards 
_ and forwards. It consists of several small la- 
mine separated by their fissures. Behind it is 
_ a larger lobule, which forms the most prominent 
Fig. 
691 
portion of the inferior vermiform process, called 
by Reil, from its form, the pyramid. Its apex 
is directed downwards and backwards, and it 
likewise consists of numerous small laminz. 
These lobules of the inferior portion of the 
median lobe serve to connect others of the 
lateral hemispheres. The spigot connects the 
almond-like lobes; the pyramid the biventral 
and the slender lobes. 
Posterior to the pyramid are a series of la- 
mine which extend to the posterior notch and 
form its floor. These pass directly from one 
side to the other, their free margin being con- 
vex and directed backwards. They connect 
the posterior inferior lobes. And some of the 
most anterior of them, which do not project to 
the surface, connect the slender lobes as well 
as some of the anterior lamin of the posterior 
inferior lobes. These latter lamine of the in- 
ferior vermiform process, Reil distinguishes 
by the name of long and hidden commissure 
(langen verdeckten Commissur ), and the former 
constitute his short and exposed commissure 
( Kurzen und sichtbaren Commissur ). 
Above the last-named commissure is a single 
lamina which forms a line of demarcation be- 
tween the inferior and the superior vermiform 
processes, serving to connect the upper and 
posterior lobes of the hemispheres. This is the 
single commissure (einfache quer Commissur ). 
It will serve to elucidate the foregoing neces- 
sarily intricate description, if I sum up with 
391. 
Inferior surface of the cerebellum. 
V, inferior vermiform process ; p, posterior pyramids ; r, restiform bodies. 
the following enumeration of the lobes of the 
hemispheres, specifying at the same time the 
commissures by which they are connected, i. e. 
* Although it does not appear that Reil used the 
microscope, his statement respecting the structure 
of these wings is perfectly correct. 
the lobes of the superior and inferior vermiform 
processes which serve that purpose. _ 
1. On thesuperiorsurface of the hemispheres. 
‘a. The square lobes, consisting of eight 
lobules, which are connected by as many, or 
nearly so, of the superior vermiform process. 
2x2 
