Efferent Neurones in the Electric Lobes. II 
neurones of the electric organ give numerous processes from 
the cell-body. In the former case, the meshes of the reticu- 
lum are changed gradually from a regular polygonal form 
to those much drawn-out in the axone hillock. In the 
case of the Torpedo, however, the arrangement of the 
reticulum is modified not only toward the axis cylinder, but 
in every part of the cell-body from which dendritic processes 
arise. The appearances in Torpedo can be explained as a 
result of the growth changes of the cell-body. Judging from 
what we find in the rat, we assume in the first place the spinal 
ganglion cell to be a spherical mass filled by the wide meshed 
reticulum. For the same reason we assume that this spheri- 
cal mass is pulled out at each point where there is a dendrite, 
and thus modified as it is where the neuraxone is formed 
from the axone hillock. Asa result, the primitive polygonal 
meshes are transformed mechanically by the growth changes 
and thus give rise to the fibrillar appearance. If numerous 
processes are formed by the cell, as in the case of Torpedo, 
’ then the resulting appearance is quite complex. But the 
principle of its formation is the same as in the more simple 
spinal ganglion cell. The so-called fibrillar arrangement 
in the writer’s preparation is thus explained: 
V.—SUMMARY. 
1. The efferent neurones of the electric lobes of Zorpedo 
occidentalis present a fibrillar appearance of the ground 
substance. 
2. This appearance, however, is due to an alteration in the 
shape of the meshes of the reticulum, and, therefore, it can- 
not be compared with the fibrils described by Bethe, Apathy, 
and others. 
3. The meshes of the reticulum, which are regarded as the 
primitive by the present writer, are altered by the growth of _ 
the cell-body where the processes, both axone and dendrite, 
arise and become extremely elongated in these branches. 
4. Gradations from the primitive shape of the meshes to 
the altered form which appears fibrillar, are clearly visible in 
the spinal ganglion cells of the white rat. 
II 
