582 
a partial septum, divides a superficial space 
from the general submucous tract; and it is 
necessary to understand this arrangement, in 
order to apprehend the mode in which the sub- 
maxillary g'and approaches the mucous mem- 
brane of the mouth: the gland lies in the su- 
perficial division of the space, and it is round 
the posterior edge of the mylo-hyoid muscle 
that its duct is reflected in proceeding to dis- 
charge itself, which by so entering the sublin- 
gual space it is enabled to do. The anterior 
division of the digastric space contains, super- 
Sicially the gland just mentioned, the facial 
artery and vein with some of their branches, 
the mylo-hyoid twig from the third division of 
the fifth, and many lymphatic ganglia. The 
gland receives a thin capsular investment from 
the deep surface of the fascia, closing the space, 
and this prolongation contracts and condenses 
itself round the posterior extremity and duct, 
accompanying these in their turn round the 
mylo-hyoid, and furnishing the duct with a 
dense fibrous tunic. The artery enters the 
space from below, by passing beneath the pos- 
terior belly of the digastric muscle, very tor- 
tuously winds through the submaxillary gland, 
and bends over the basial edge of the jawa 
little in front of the masseter. It furnishes a 
deep ascending branch (the tonsillary) near the 
angle of the jaw and many glandular twigs; 
but its only considerable branch in this region 
is the sub-mental, which runs toward the me- 
dian line just beneath the jaw, and, supplying 
the mylo-hyoid muscle on which it is applied, 
and the anterior belly of the digastric, termi- 
nates by freely communicating with its fellow. 
The sub-mental branch derives additional im- 
portance from the frequency of an anomalous 
distribution, by which, a the mylo-hyoid 
muscle and entering the sublingual space, it 
partly discharges the functions of the lingual 
artery in supplying the sublingual gland. The 
facial vein lies behind the artery, and quits the 
space below in passing over the digastric and 
stylo-hyoid muscles, which divide it from the 
artery. Its usual or chief termination is in the 
internal jugular; but it frequently contributes 
more or less to form the external or the ante- 
rior jugular vein. The mylo-hyoid nerve runs 
parallel to the origin of the muscle, which gives 
it its name, and supplies it and the anterior 
belly of the digastric. The lymphatic glands 
are numerous and important: they receive the 
absorbent vessels from the face and likewise 
from the mouth and pharynx, are the frequent 
seat of strumous inflammation, readily sympa- 
thize in disordered conditions of the fauces and 
alveoli, and take an active part in propagating 
the malignant influence of cancerous ulcerations 
on the face. These parts are all covered in by 
the aponeurosis,—which fixes itself to the base 
of the jaw,—and by the platysma and superficial 
fascia,—which continue themselves on the face. 
They are readily accessible to the surgeon, but 
seldom subjected to any operation of impor- 
tance. The deep or sublingual portion of the 
digastric space has its roof formed by the mu- 
cous membrane, which, between the tongue and 
alveolar arch, constitutes the floor of the mouth; 
NECK. 
the side of the tongue and the continuous sur- 
face of the pharynx, as already described, com- 
pose its inner wall; and it follows from the — 
previous description that, in part at least, the — 
mylo-hyoid is its floor. The gustatory nerve — 
runs through it beneath the mucous membrane, 
which it supplies: the hypo-glossal, describing” 
a parallel but inferior curve, is distributed in — 
succession to the muscles of the inner wall of 
the space ; the glosso-pharyngeal between these 
two in height, but confined to the root of the 
tongue, bends inwardly beneath the ylo- 
glossus; the lingual artery, emerging from 
under cover of the hyo-glossus, which has 
hidden its tortuous ascent, divides anteriorly 
into two branches; a ranine, which follows the - 
curved border of the tongue to its tip, where 
archingly unites with its fellow; a sublingual ey 
which directing itself a little outward, supplies — 
the third salivary gland: this little body lies on 
the divergent fibres of the genio-glossus, near 
their origin, and close beneath the membrane 0 
the mouth : finally, the duct of the submaxillary” 
gland, traversing the space obliquely, era 
contents, and communicates with the cavity o 
the mouth just beside the frenum. This space 
is the seat of ranula (a tumour formed by ob 
struction of the submaxillary duct), and ¢ 
some salivary concretions ; in both which com 
plaints the distended canal is brought soimme- 
diately beneath the mucous membrane, whic! 
it raises, that other parts are little liable to | 
jury: here, too, it is that the surgeon, wher 
obliged to divide the frenum lingue, mi 
cautiously cut the too tight fold near to th 
symphysis, and vertically, lest, in extendit 
his incision backward, he should wound # 
ranine artery. Sharp instruments penetrat 
downward beside the tongue may wound - 
sublingual artery, and the consequent heme 
rhage, distending the submucous space, ra 
the reflected membrane on each side into swe 
ings of such size, as to suggest imminent pe 
of suffocation.* .. 
7. The small region to oa under» 
name of posterior pharyngeal, zi" 
brief notok; has tbr its roof the benllar rt 
of the occiput and petrous part of the temy 
bone, and presents in this direction the or 
of the jugular, carotid, and anterior cond 
canals: it extends downwards between the 
rynx and vertebre into the anterior tri 
the neck, and is separated from the post 
division of the digastric space, within wh 
lies, by the styloid and vaginal processe 
by the attachment to these of a strong 
fascia, which passes beneath the digastric 
cle. The internal carotid artery, surround 
branches from the superior cervical gan 
* Such an accident I have seen arise frot i 
inadvertent thrust of a tobacco-pipe ; the sw 
was very considerable on both sides, and 
duced alarming distress. Cold (aided, no dot 
by the pressure of the effused blood) succeed 
staying the hemorrhage ; had this not been 
case, it would have been neeessary to xpos 
lingual artery on the cornu of the os h es 
to secure it; or, had its ligature not sufficed, 
wise to tie the adjoining trunk of the facial, 
* 
which the sublingual branch is occasionally deri 
