— ii8 — 
system. Their function is, in my opinion, of nutritive nature, as 
mentioned before. ^) 
The contents of the nervous processes consists of primitive tubes. 
The nervous processes (as well as the protoplasmic ones) are 
enveloped by neuroglia-sheaths adherent to which neuroglia-nuclei 
may be seen. 
The nuclei of the ganglion cells have a structure similar 
to what is before mentioned as regards the nuclei of the cells of 
Homarus etc. 
They are generally situated in, or towards, that pole of the cell 
from which the nervous process issues. Sometimes they are also 
situated in the mesial part of the cell and very seldom in the end 
opposite to the nervous process. 
They have a relatively large size; when they are situated near 
the origin of the nervous process, they generally fill nearly the 
whole diameter of the cell, leaving only a narrow layer of proto- 
plasm, through which the connection of the nervous process with 
the upper principal part of the protoplasm is produced (vide fig. 53). 
Frequently the space between the nucleus and the membrane en- 
veloping the cell is, however, so extremely narrow, that it looks as 
if only a very few primitive tubes could pass; it has, indeed, the 
appearance as if the protoplasm of the ganglion cell was almost 
divided by the nucleus into two separate parts. 
In one case I have seen a nucleus sending a short process into 
the nervous process (vide fig. 54); this short process was very 
distinct, and appeared to be formed by the nuclear membrane; it 
may be that it has only been an artificially produced, post-mortem, 
appearance. 
The neuro glia-memhr anes enveloping the ganglion cells 
are thin and but slightly prominent. Neuroglia-nuclei, adherent to 
them, are occasionally seen. They are intimately connected with the 
neuroglia reticulation extending between the ganglion cells (fig. 
48 — 50, nur). When HALLER and Rawitz seem to deny to some 
extent the existence of such membranes, I think that it is owing 
^) In the peripheral layers, almost all cells have unipolar shape, in the inner 
layers (towards and in the dotted substance), the bipolar or multipolar shape is more 
common; as will later, in a separate chapter, be treated of, this also indicates the 
nutritive significance of the protoplasmic processes. Real anastomoses of proto- 
plasmic processes from the same cell, or from various cells, I have never been able 
to observe, and do not believe either in their existence or in the significance 
which Haller and most writers attribute to those processes (vide sequel). 
