— lOI — 
In connection with these membranes we find, however, a very 
strange structure. In B it has the appearance as if a series of deeply 
stained oblong corpuscles were situated along the inner side of the 
membrane. Upon closer examination we will see that these cor- 
puscles are, as a rule, connected with the membrane by very 
slender filaments. In some cases these filaments are even very thick 
and the dark corpuscles appear thus to be transsected fibres or septa 
issuing from the membrane {cmfr. fig. 24, b). On the other side 
we will, on close examination, find slender filaments issuing from 
the inner extremities of those dark corpuscles or fibres and pene- 
trating into the protoplasm of the cells; indeed, we will see that 
they anastomose and form a reticulation, extending through the 
cell-protoplasm and distinctly visible in its outer layers. The 
meshes of this reticulation are also largest in the outer layers near 
the surrounding membrane (vide fig. 24). They have, here, very 
often, an oblong form, going in a radiate direction towards the centre 
of the cells, and having, sometimes, the appearance as if the meshes 
were formed by filaments radiating from this centre to the surround- 
ing cell-sheaths ; in fig. 24 B such an arrangement is very distinct. 
Within these large meshes smaller meshes are generally seen (fig. 24). 
These smaller meshes have, however, a somewhat different appear- 
ance, they being not so distinctly visible; I am not sure whether 
they are formed in quite the same way. 
Towards the inner part of the cell-protoplasm (which is more 
deeply stained) the meshes of the first mentioned reticulation be- 
come much smaller and become similar to the small meshes just 
mentioned, indeed, they cannot be distinguished from each other. 
The meshes are so narrow that they are visible only under the 
higher powers of the microscope, and, even then, not very distinctly ; 
in small cells they are especially very difficult to observe. 
In the filaments of this reticulation, granules and thickenings 
occur, giving the cell-protoplasm, seen under lower powers of the 
microscope, a granular appearance. These thickenings are, especially 
in the large ganglion cells, very prominent in the outer layers of 
the protoplasm. 
In the small meshes of this reticulation, a hyaline substance is 
suspended, very similar to the hyaloplasm of the nerve-tubes. 
The question which now, as regards the reticulation, very na- 
turally forces itself upon us is, whether is it a real spongy reticulation 
extending through the protoplasm of the cells, or is it a reticulation 
produced by a transsection of tubes in the same way as we have 
