78 
BULLETIN OF THE LABORATORIES 
and after penetrating the layers of the granular zone their fibres con- 
tinue toward the crus. It has not proven possible to determine 
whether the fibres anastamose and form a reticulum or whether there 
is one main branch and lateral nutrient roots as claimed in other 
cases. Our own impression is that there is considerable lateral anas- 
tamosis in the neuroglia layers and that fibres after passing into the 
granular layer soon again acquire medullary sheaths. If, as we be- 
lieve, the ganglion cells are to be compared with the cells of the spinal 
ganglia, it would appear that this locus is a point where nourishment 
is received and hence the myelin sheaths must be interrupted. This 
space devoid of medullary sheaths is richly supplied with the Deiter’s 
cells which convey the nourishment and also affords the opportunity 
for intercommunication. The ganglion cells are comparatively large 
and bear a close resemblance to those of fishes, for example. The 
nuclei seem to be normally ovoid ; but the cells frequently shrink dur- 
ing preparation and this shrinkage especially affects the nucleus. 
4. The granular layer is well developed and laminated, each 
lamina being separated by tracts accumulated from the entad processes 
of the ganglionic cells. The fibres near the tip seem to pass almost 
directly through this layer to accumulate at the ventricular surface 
where they have been considered as forming a part of the pes though 
actually belonging to the pero. Farther caudad the course of the 
fibres is oblique. Two different types of corpuscles may be distin- 
guished in these granular laminae, one being globular and rather larger 
than the ovoid and darker bodies which we have supposed might be 
those connected with the function of formation of sheaths for these 
fibres, while the former would retain the more purely nutritive func- 
tion. 
The pes. Cephalad the ventricular epithelium alone represents the 
core of the lobus olfactorius. The epithelium resembles that of other 
parts of the ventricular system. A few connective fibres extend into 
the granular layer and bear the usual dark inoblastic nuclei. Near 
the point where the lobe joints its crus the pes develops a different 
ental structure. Here there is an invasion of cortex from the cere- 
brum. These cells exhibit no orderly arrangement cephalad, but are 
irregularly disposed and are pyramidal and deeply staining. The area 
is triangular, being bounded caudad by the peculiar structure of the 
post-rhinal lobe, from which it is separated by a distinct fibre tract. 
