_Contusion_;
_Wounds_; _Fractures_--Injuries of eyeball--Orbital
cellulitis--Tumours. LIPS--_Cracks_; _Chronic induration_;
_Tuberculous ulcers_; _Syphilitic lesions_--Tumours: _Naevi_;
_Lymphangioma_; _Cysts_; _Epithelioma_.

THE FACE

CONGENITAL MALFORMATIONS.--The description of the various congenital
malformations of the face will be simplified by a brief consideration
of its development.

_Development._--About the middle of the first month of intra-uterine
life the prosencephalon bends acutely forward over the end of the
notochord and sends out from its base a series of processes, which
ultimately blend to form the face (Fig. 231). These processes surround
a stellate depression, the primitive buccal cavity or stomatodaeum,
from which the mouth and nasal cavities are developed. The buccal
cavity is bounded above by the fronto-nasal process, which is divided
by a fissure--the nasal cleft or olfactory pit--into a lateral nasal
process, and a mesial nasal process, at the outer angle of which a
spheroidal elevation appears--the globular process.

[Illustration: FIG. 231.--Head of human embryo about 29 days old,
showing the division of the lower part of the mesial frontal process
into the two globular processes, the intervention of the nasal clefts
between the mesial and lateral nasal processes, and the approximation
of the maxillary and lateral nasal processes, which, however, are
separated by the nasal-orbital cleft. (After His.)]

From the mesial nasal and globular processes the septum of the nose,
the mesial segment of the premaxillary bone, and the middle portion of
the upper lip are developed; while the lateral nasal process forms the
roof of the nasal cavity, the ala nasi and adjacent portion of the
cheek, and the lateral segment of the os incisivum or premaxillary
bone. Each segment of the os incisivum carries one of the incisor
teeth, and each of the mesial segments may contain in addition an
accessory tooth. The nasal cleft ultimately becomes the anterior
nares.

The primitive buccal cavity is bounded below by the mandibular arch,
which contains Meckel's cartilage, and from which are developed the
mandible, the lower lip, and the floor of the mouth.

From the lateral and back part of the mandibular arch springs the
maxillary process, which grows upwards and blends with the lateral
nasal process across the naso-orbital cleft--the deeper portion of
which persists as the nasal duct. Fro