468 THE AMERICAN .NATURALIST. (VoL. XXXIV. 
of the leech and outlined on the left side in accordance with 
the older methods and on the right after Apathy. It: will 
be seen at once that Apáthy's methods have to do with the 
interior of neurones, whereas the older methods dealt with their 
outlines only. When the fibrillz so clearly demonstrated by 
Apathy are traced, they are found to begin in some cases possi- 
bly between the external epithelial cells of the skin, in. most 
cases certainly within these cells, around whose nuclei they 
form a network, after which they extend as. bundles of fine 
fibrils (sensory nerve fibres) to the central nervous organs. 
Here they separate, and either enter into the formation of a true 
network (in what has been called the neuropile) or pass at once 
into a ganglion cell, in the substance of which they form a net- 
work. Ganglion cells of this structure are supposed to be sen- 
sory (Fig. 4, S). Motor ganglion cells (77) are also penetrated 
by the fibrils from sense organs, which then form a branching 
system just within the periphery of the cell. From this periph- 
eral system (external plexus) branches extend inward to unite 
around the nucleus in a second system (internal plexus), from 
which a single large fibril emerges to make its way eventually as 
the transmitting organ of a motor fibre to a muscle into whose 
fibres it may enter after branching. These fibrils are the trans- 
mitting organs of the nervous system and are called by Apáthy 
* neuro-fibrils "; and what is most characteristic about them is 
that, from their beginnings in or about the sensory cells to their 
endings in the muscles, they are absolutely continuous; they 
branch and recombine, but they never show lack of continuity ; 
and this continuity of the fibrillar substance is the feature that 
characterizes what has been called the fibrillar te 
supposed opponent of the neurone theory. - 
Apáthy's opposition to the neurone theory does not stop here: 
for he has.a conception of the structure of the nervous system 
quite at variance with the tenets of this theory. He holds that 
the cells connected with) nervous operations are of two kinds, 
which he calls nerve cells and ganglion cells. ; Nerve. cells are 
those cells that produce fibrillar substance, and this substance 
in its growth enters sensory cells, ganglion cells, muscle cells, 
etc.; in short, it is the means of binding the whole nervous 
