298 
optic ganglion, contains the most interesting cells met with in the 
central nervous system. The cells possess nuclei with nucleoli, inclusions 
and vacuoles. The inclusions have been well described by SAmassa 
and I can confirm all of his statements. That their form is variable 
is well shown in figures 2—10. There may be several in a single 
cell. They are deeply impregnated with gold chloride and stain deeply 
with the EnrticH -BıoxpI- HEIDENHAIN mixture and HEIDENHAIN’S 
haematoxylin. The cells, as SAMASSA states, are irregular in outline, 
due to mutual compression. 
Samassa describes the cells as having no processes and says they 
only touch the medulla occasionally at the upper part. From careful 
study I can say that this is incorrect. They have processes which 
are not difficult to show in sections cut in favorable planes. The 
processes are several in number and are directed into 
the pre-central medulla. This is plainly shown in figures 8, 9, 
10 and 11. But in figures 2—9, inclusive, the fact is also evident 
for the cells can be traced along until they split up into several 
processes, which enter the pre-central medulla. Few cells in any 
series show the processes passing directly into the medulla, since they 
converge from the dorsal and lateral parts to this point. I hope to 
be able in the future to indicate the exact nature of these processes 
with the aid of Gorer’s silver methods. 
SAMASSA also states that the optic commissure passes through 
this group. This I am unable to confirm. The optic nerves pass 
between the cortical cells and the lateral continuation of the small 
and medium-sized cell group. The nerves are seldom in contact with 
the giant cells laterally. In figures 5—9, inclusive, these cells are 
not all shown in the drawings. 
SAMASSA states that the cells of the optic ganglion are in intimate 
relation with the giant cells. ‘This is only partly correct, according 
to my investigation. Somewhat dorsally, the giant cells are separated 
from the cells of the optic ganglion by a continuation of the cortical 
cells and the small and medium-sized cell group. Ventrally, the giant 
cells come to the surface of the brain as they do dorsally and there 
is no connection with the optic ganglion. In some sections, however, 
it is extremely difficult to draw a line between these small cells and 
those of the optic ganglion; yet most of the small cells near the giant 
cells are directed away from the optic ganglion and there is a difference 
in size. 
Internal structure of optic ganglion. This is best 
determined in sections out parallel with the dorsal surface. The 
