120 Wicriam A. Hıvron, 
in iron-hematoxylin. A few cells, already mentioned, were found 
outside the connective-tissue mass, and some were found imbedded 
in it. The thickness of the outer layer of nerve cells in the ganglion 
differed considerably in various parts of the same specimen. Some 
of this difference was due to differences in the plane of sectioning. In 
places the cells became reduced to a single irregular layer, but in 
most regions more were seen (Figs. F, G). The average number of 
cell layers might 
be said to be three; 
in some places there 
were many more 
than this. Some of 
the larger elements 
were often found at 
the outer edge of 
the ganglion, many 
of these were seen 
to send a large 
process in towards 
the center. I am 
inclined to think 
that most of the 
larger ones at the 
outer edge are of 
this sort. The 
branches often run 
in straight towards 
oe m A ee. the center and are 
ig. G. Diagram of the ganglion of Tunica nigra ; 
as seen in a es section which nee through a ape easily followed for 
and a small branch. Drawings of actual cells from various some distance. 
regions are placed in this diagram. Some of the longer ‘ 
processes from nerve cells into the nerve trunk are repre- Other cells send 
sented quite diagrammatically, because, so far as could be their processes to 
determined, most peripheral cells send fibers for longer or 1 a1 ; 
shorter distances along the axis of the ganglion before the central area, 
entering the nerve trunks. 250:1. but not straight in. 
The direction in 
which these run is variable; at the same level the process of one 
cell may be sent obliquely in one direction part way to the 
center, and near this another cell may send its process obliquely 
in the opposite direction, but not necessarily at the same angle. 
Cells of smaller size in the other layers at the periphery were 
