es apart from fracture. Complete and permanent
deafness results. Effusion of blood into the nerve sheath, or into the
internal or middle ear, causes transitory deafness, and the patient
suffers from noises in the ear, giddiness, and interference with
equilibration.

IX. The _Glosso-pharyngeal Nerve_ is comparatively seldom injured.
When it is compressed by a tumour in the region of the medulla, there
is interference with speech and deglutition, ulcers form on the
tongue, and oedema of the glottis may supervene.

X. The _Vagus_ or _Pneumogastric Nerve_ is seldom injured within the
cranial cavity.

In the neck, it is liable to be divided or ligated in the course of
operations for the removal of malignant or tuberculous glands, for
goitre, or for ligation of the common carotid. Division of the nerve
on one side, or even removal of a portion of it, is not as a rule
followed by any change in the pulse or respiration. If it is
irritated, however, for example by being grasped with an artery
forceps, there is inhibition of the heart, and if it is accidentally
ligated, there may be persistent vomiting.

Division of the main trunk, or of its recurrent branch on one side,
results in paralysis of the corresponding posterior crico-arytaenoid
muscle--the muscle that opens the glottis. This condition is known as
unilateral _abductor paralysis_, and is accompanied by interference
with inspiration and phonation. If both nerves are divided, bilateral
abductor paralysis results: the vocal cords flap together, producing a
crowing sound on inspiration and embarrassment of breathing, and
tracheotomy may be necessary to prevent asphyxia.

The vagus and recurrent nerves have been successfully sutured after
having been divided accidentally.

XI. _Accessory_ or _Spinal Accessory Nerve_.--This nerve is seldom
damaged within the skull. It supplies the sterno-mastoid and
trapezius; but as these muscles usually have an additional nerve
supply from the cervical plexus, the accessory may be divided, or a
considerable portion of it resected, as, for example, in the treatment
of spasmodic torticollis, without any serious disablement resulting.
It is liable to be accidentally divided in excising malignant or
tuberculous glands in the neck. When, however, the accessory is the
only source of supply to these muscles, its division is followed by
considerable disablement, which appears to depend almost entirely on
the _paralysis of the trapezius_. The