630 
MR. YOUATt's veterinary LECTURES. 
4. The PatheticuSf from a little sulcus on the crura cerebri at 
the base of the testes to the superior oblique muscle,— a nerve of 
voluntary motion. 
5. The Trigeminus, evidently proceeding from two roots; the 
inferior one from the crus cerebri —the superior one from the 
crus cerebelli. The superior one forming or passing through a 
ganglion—the inferior one unconnected wdth the ganglion, but 
uniting w'ith the other branch immediately beyond the ganglion ; 
and both contributing to form one compound nerve distributed 
over the face— a mrve of common sensatioji and of voluntary 
motion. 
6. The Abducens, from a transverse sulcus between the pons 
varolii and motor root of the eighth pair (the portio dura of the 
seventh), and going partly to the retractor, but principally to the 
abductor muscle of the eye,— a nerve of voluntary motion. 
7. The Voluntary and Organic Motor Nerve of the Face, 
in the old nomenclature the portio dura of the seventh, springing 
evidently from two roots; the first to be traced from the central 
column of the inferior surface of the medulla oblongata, and 
the other from the head of the lateral column, or corpus olivare, 
if it may be so termed in the quadruped ; united together as 
they escape from the brain, and forming a compound nerve,— 
the voluntary motor nerve of the face ; and directing also those 
motions,partly voluntary and partly involuntary, which are con¬ 
nected with the respiratory system of organic life. ■ 
8. The A uditory (the portio mollis of the seventh), traced 
from the floor of the fourth ventricle; passing down the side of 
the medulla oblongata; entering into the same sheath with the 
eighth (the portio dura); escaping through the foramen audi¬ 
torium internum, and spreading its pulpy ramifications over the 
internal chambers of the ear,— a nerve of peculiar sensation, and 
affected onl}" by the vibrations of the air. 
9. The Glosso-Pharyngeus, arising from the lateral column of 
the medulla oblongata by several little filaments, partially rami¬ 
fying over the constrictor muscles of the pharynx, but chiefly 
expended on the base and substance of the tongue. An organic 
motor nerve, associating the action of the muscles of the pharynx 
and tongue with the discharge of the functions of respiration and 
deglutition. 
10. The Par Vagum of our anatomists—the pneumo-gastric 
nerve of the French, but, more properly, the cerebro-visceral 
organic motor nerve. It arises from the lateral column of the 
medulla oblongata, by numerous filaments, a little posteriorly to 
the glosso-pharyngeus, and escapes from the cranium in the 
same sheath with it. After distributing several branches to the 
