forward except when the tumour is growing in
the optic nerve or its sheath. When the tumour is solid, the eye
cannot be pressed back into the orbit, but in cystic tumours it may to
some extent. The movements of the eyeball are restricted in a varying
degree, and ptosis often results from paralysis of the levator
palpebrae superioris. In almost all cases there is also more or less
visual disturbance. The cornea being unduly exposed is liable to
become inflamed, or even ulcerated. Pain is a variable symptom; when
present, it usually radiates along the branches of the first and
second divisions of the trigeminal nerve. Tenderness on pressure is
not always present. It is comparatively uncommon for a tumour of the
orbit to invade the globe directly.

[Illustration: FIG. 238.--Sarcoma of Orbit, causing exophthalmos and
downward displacement of the eye, and projecting in temporal region.]

[Illustration: FIG. 239.--Sarcoma of Eyelid in a child.

(Mr. D. M. Greig's case.)]

_Treatment._--When practicable, removal of the tumour is the only
method of treatment, and in malignant tumours it is often necessary to
sacrifice the eye to ensure complete removal. When the tumour has
invaded the orbit secondarily, its removal may be impossible, but it
may be necessary to remove the eye for the relief of pain.

The _orbital dermoid_ usually occurs at the lateral end of the
supra-orbital ridge (Fig. 240). A less common situation is the
anterior part of the orbit, near the nasal wall, and this variety,
from its position and from the fact that it is usually met with in
children, is liable to be confused with orbital meningocele or
encephalocele. Treatment consists in its removal by careful
dissection, and this can usually be done under local anaesthesia.

[Illustration: FIG. 240.--Dermoid Cyst at outer angle of orbital
margin.]

_Orbital aneurysms_ have already been described, Volume I., p. 317.

THE LIPS

_Herpes_ of the lips, due to a mild staphylococcal infection, is
common in delicate children and in the early stages of pneumonia. A
crop of vesicles forms and, after bursting, these leave dry scabs.

A more severe staphylococcal infection may give rise to a carbuncular
swelling with great oedema, and lead to infective phlebitis of the
facial vein and general septicaemia. Excision of the focus is
indicated.

The lip is sometimes the seat of the malignant pustule of anthrax.

Painful _cracks and fissures_ are frequently met