— I09 — 
ganglion cell, this difference being, as we have seen, already distinct 
within the cell itself. It has, in preparations often, the same light 
staining the whole way from the origin of the nervous process till its 
entrance into the dotted substance (fig. 35); generally it is, however, 
stained in a quite peculiar manner by hæmatoxylin. Fig. 30 — 33 
represents various sections through a such process; it is the same 
process the contents of which is also seen in fig. 28 and 29. At 
the agress from the ganglion cell (fig. 30), the contents of the 
nervous process has the same light staining as already described. 
At some distance from the cell the contents begins, however, to get 
a darker, more black staining, especially in its peripheral layers (fig. 31). 
At the same time the diameter becomes also diminished. At a 
greater distance from the cell this blacker staining increases, and the 
whole contents is stained quite dark or black (fig. 32), the diameter 
of the process is also still more diminished. In fig. 33, the same 
process is seen divided into two branches [a and h) which have the 
same black staining as above. This black staining they retain till 
their entrance into the dotted substance. The branchlets issuing from 
them are also stained in the same manner. It is, of course, very 
difficult to say what is the reason of this dark staining. I do not 
think, however, that it is of qualitative nature. To some extent it 
may, perhaps, be explained by the relatively small thickness of the 
processes, and by their situation in a reticulated neuroglia through 
which the fixing as well as the staining agents easily find their way to 
these structures. It is, however, strange that, in the same section, 
one can find some processes with dark contents, and other processes 
with light contents, similar to the contents of the nerve-tubes (cmfr. 
%• 35 & 36)- The branchlets issuing from these processes have 
similar lightly stained contents, consisting of primitive tubes (cmfr. 
fig. 35, 6r; fig. 36, hr, Ir'). 
Spongioplasmic fibres similar to those surrounding the process- 
contents within the ganglion cell (cmfr. fig. 28 & 29, also, generally 
occur in the process itself They have a longitudinal course along 
the process, inside the sheath (vide fig. 30, sf , sf ) and can often be 
traced to a considerable distance from the ganglion cell (vide 
35> sf). They have a dark staining; sometimes it looks as if 
they united to form a deeply staining peripheral layer round the 
contents of the process inside the sheath (fig. 36). 
The sheaths of the nervous processes are formed by the 
neuroglia, and are stained in the same manner as this substance. 
They have generally a peculiar structure, and consist often of a great 
