A os 
is usually associated with a flattening or indentation of the pole of the 
cell with which it is in contact. 
A third variety of ending found in this region is called by v. Len- 
hossék a ,polares Geflecht”, but I prefer to designate it as an arbo- 
rescent ending, since I cannot convince myself that anastomoses 
occur between its numerous branches. This type, illustrated by Figure 
9, is plainly a development of the brush ending just described. The 
subdivision of the main end branches of the oculomotor fiber is carried 
to a greater extent, the result being a complicated arborization, the fine 
branchlets of which cross one another in various directions, but probably 
do not unite to form a veritable network. The question of the existence 
of true end plexuses about the cells of the oculomotor portion of the 
ganglion will be discussed after the description of the type of ending 
which characterizes the trigeminal region. 
Nerve Endings in the Trigeminal Region. The fibers 
which enter the ciliary ganglion from the ramus communicans trigemini 
terminate on the nerve cells situated in the portion of the ganglion 
described above as the trigeminal region. The cells here are also uni- 
polar (Fig. 10). The amphicyte nuclei found in their capsules are usually 
evenly distributed. The endings of the fibers of the radix longa never 
take the forms just described for the oculomotor region. They are always 
end nets or plexuses (Pig. 11, 12, 13). The fime trigeminal fiber, 
easily told from the large oculomotor neurite by its smaller size (com- 
pare Fig. 3 to 9 with Fig. 12 and 18), gives rise by branching to an 
intracapsular, pericellular complex of fibrils. These are arranged in an 
irregular way over the surface of the cell, and apparently anastomose 
to form true networks or plexuses. Here and there along the fibrils may 
be seen small expansions which appear granular under the oil immersion. 
In many cases short side branches are given off, which end freely in 
slight terminal swellings, also distinctly granular in appearance. These 
terminations are not always in contact with the surface of the cell, but 
may he in the space between the latter and its capsule, where amphicyte 
nuclei are also found. v. Lenhossék (:11), in describing such a relation 
between the arborescent endings of the oculomotor fibers and the nerve 
cells, suggests that this arrangement may indicate that the nervous im- 
pulse passes from one neurone to the other by means of a kind of in- 
duction. 
The trigeminal region of the hen’s ciliary ganglion is, then, charac- 
terized by these end nets. In the cephalic and central portions of the 
region only end nets are present — not a single end calyx or other 
oculomotor termination is to be seen. But as we approach, in the caudal 
or proximal direction, the zone lying between the trigeminal and ocu- 
