( 705 ) 
a hollow outgrowth from the base of the hemisphere vesicle. On 
the external surface of the lateral wall of the hemisphere, the lobe 
is limited by a shallow sulcus, the fissura rhinica. This suleus runs 
in a fronto-occipital direction (fig. I, I, HI PF. rh). On the external 
surface of the mesial wall of the hemisphere vesicle the olfactory 
lobe is bordered by a very broad suleus which in the beginning 
runs also in a fronto-occipital direction but bends afterwards more 
vertically. This suleus is the fissura prima of His and only to be 
seen in the first two figures (fig. I, IL F. pr.). 
Bordered by these two grooves the olfactory lobe shows a double 
curvature from lateral to mesial and slightly from behind forwards. 
The anterior cornu of the lateral ventricle forms a prolongation in 
the olfactory lobe reaching into the top of the bulb. This cavity 
shows the same curvatures as the lobe, which can partly be seen 
from the diagrammatic figure V. In its general feature and apart 
from its curvatures this cavity of the olfactory lobe has the shape 
of a funnel, the mouth turned to the lateral ventricle the tube to 
the top of the olfactory bulb. 
A close relation between the form of the external and internal 
surfaces of the hemisphere vesicle does not exist. The internal surface 
of the lateral wall is thickened by the appearance of the corpus 
striatum. This thickening of the wall begins wellmarked at some 
distance (2mm) from the top of the hemisphere vesicle; a prolonga- 
tion of this thickening, described by His as the “Crus epirhinicum”, 
which, along the top of the hemisphere unites the striatum with the 
rhinencephalon does not seem to exist. The ventral edge of the striatum 
is also clearly marked by a prominent crest, the crista ventralis 
corporis striati; (fig. I, Cr. v. str.) which is bordered by a deep sulcus 
(fig. I, S. v. str.). This suleus on the internal surface of the vesicle 
does not agree in all respects with the fissura rhinica on the external 
surface. 
The ventral edge of the striatum first proceeds in a fronto-occi- 
pital direction and then turns more ventrally over the posterior wall 
of the funnellike outgrowth of the rhinencephalon. By its typical 
configuration it is easy to follow this ventral edge of the striatum 
till it goes over in an analogous formation belonging to the rhinen- 
cephalon. 
This formation of the rhinencephalon appears as a thickening of 
the internal surface of the mesial wall of the hemisphere vesicle. It 
begins pretty well marked a little more distant from the top of the 
hemisphere than the striatum. Dorsally and ventrally this thickening 
is limited by a deep groove, the suleus rhinencephali dorsalis and 
