Central nervous system of Tunica nigra. 121 
also seen sending branches to various parts of the central fibrous 
portion of the ganglion (Figs. G, H). A few of the larger more 
superficial cells of the ganglion were seen to send their processes 
out into the connective tissue and in some cases apparently beyond 
this, rather directly into nearby muscle fibers; some of these were 
undoubtediy the fibers indicated in the model by the smaller median 
dorsal branches, but it seems probable that some cells as individuals 
send fibers directly to muscles. 
Some of the cells of the peripheral zone could be seen sending 
processes in among others of this denser mass and in exceptional 
places a few fibers of this sort were seen inside the general mass 
of the ganglion. Association cells of large and small size were seen 
in the midst of the thickened mass. Branches were also seen coming 
from cells of various levels and running just inside the cortex. 
Some of these, of course, may have had some efferent fibers as well 
as association branches. Fibers, apparently for associating various 
parts of the denser mass at the periphery, were seem to come from 
cells of all sizes and from all levels, but chiefly from those near 
the middle of the ganglion. The fibers of these cells at the point 
of their passage from the peripheral to the deeper layer turn rather 
abruptly to run for longer or shorter distances along the inner 
boundary of the peripheral area. Cells of the superficial layers and 
those farther in towards the center, such as have already been 
mentioned, usually have one process considerably larger than the 
others, and in some cases no other processes were seen. Such cells 
have this portion running in towards the center of the ganglion, 
sometimes straight, sometimes twisted either near its origin or along 
its course. Another type of cell was found located at the edge 
of the ganglion with one large process extending in towards the 
center of the fibrous mass and with a large branch from this 
main one running back to another part of the dense cell area 
(Figs. G, H). 
Just inside the denser mass of cells a few scattering ones are 
often evident. These are much like those of the peripheral thicker 
mass. The larger nerve branches point in various directions, in 
some they extend out towards or into the peripheral cell layer; 
some cells send processes along the inner side of this region as 
association fibers, possibly in some cases as efferent fibers, while 
others send their main processes in toward the central part of the 
ganglion. Some cells of this inner portion of the peripheral mass 
