Sen 
962 THE DIGESTIVE SYSTEM. 9 
sides. It is enclosed in a complete capsule derived from the deep cervical fascia : 
embedded in this capsule, and superficial to the gland, are found a few submaxillary 
lymphatic glands, which are of importance owing to their connexion with the 
lympbaties of the lips and of the anterior half of the tongue. 
In considering the relations of the gland, it is well to remark that there is in this region a 
three-sided space bounded externally by the inner surface of the mandible below the mylohyoid 
ridge, internally and above by the mylohyoid muscle running inwards and downwards, and below 
by the skin and fascia passing from the margin of the jaw obliquely i inwards and downwards to join 
the side of the neck. In this space the eland hes with external, internal, and inferior surfaces 
corresponding to the walls of the space. 
The superficial or inferior surface looks downwards and outwards ; 1t is covered 
by the deep cervical fascia and the platysma, and is crossed by the facial vein, 
which lies superficial to the gland, whilst the artery passes in part beneath it. The 
external surface rests against the inner aspect of the lower jaw (submaxillary fossa) 
for an inch and a half forward from the angle, to which latter it usually reaches 
behind. The deep or internal surface lies on the posterior part of the mylohyoid 
muscle, and behind this, on the hyoglossus and the posterior belly of the digastric 
with the stylohyoid; for the gland is not contained within the limits of the sub- 
maxillary triangle inferiorly, but passes down some little distance over the digastric 
muscle. From the deep surface, anterior to its middle, a narrow tongue- like deep 
process (Fig. 647) is continued forwards beneath the mylohyoid muscle along with 
the duct. 
The posterior end ot the gland, which is its most bulky portion, either abuts 
against, or lies very close to, the sterno-mastoid, and is often overlapped by the 
lower end of the parotid gland. The facial artery, on its way to the border of the 
mandible, lies in a groove in the upper and back part of the gland. 
The submaxillary or Wharton’s duct leaves the deep. surface of the gland 
about its middle, and runs forwards beneath the mylohyoid muscle with the. deep 
process, along the upper and inner aspect of which it is placed (Fi igs. 646 and 643). 
Pursuing its course forwards beneath the floor of the mouth, on “the inner side of 
the sublingual gland, the duct crosses the hyoglossus and the venioglossus muscles, 
and finally opens on the floor of the mouth at the side of the frenulum lingue, 
where its small orifice is placed on the summit of a soft papilla (caruncula sub- : 
lingualis) close to its fellow of the opposite side. | 
While running forward beneath the floor of the mouth the duct, which is about two imches long 
(50 mim.), is crossed on its inferior aspect by the lingual nerve near the anterior border of the 
hyo-glossus, that is opposite the 2nd molar tooth. The nerve at the time is arching from the 
posterior end of the mylo-hyoid ridge (against which it les) inwards and forwards in order to 
reach the under surface of the tongue, and in this course it passes beneath the duct at the poimt 
indicated. As in the case of Stenson’s duct, the calibre of Wharton’s duct is much greater than 
that of the orifice by which it opens ; for this reason it may likewise be looked upon as forming, 
to some extent, a reservoir for the saliva secreted by the gland. 
Vessels and Nerves.—The arteries come chiefly from the facial and its submental branch : 
the veins are similarly disposed. The nerves are derived from the submaxillary ganglion (which 
lies above the deep process of the gland), and are composed of fibres from the chorda tympani, 
from the lingual, and from the sympathe tic on the facial artery. The lymphatics pass to the 
submaxillary lymphatic glands. 
Sublingual Gland.—This is an elongated almond-shaped mass, flattened from 
side to side, and much wider (from above Peery in front than behind, which 
les on the floor of the mouth beneath the plica sublingualis—a ridge of the mucous 
membrane produced by the prominent upper border “of the eland. It is usually 
from 1} to 13 inches (37 to 45 mm.) in length, whilst its bulk is about equal to 
that of two or three almonds. 
It is placed between the mandible externally, the genioglossus internally, the 
mylohyoid muscle below, and the mucous membrane of the mouth above (Fig. 637). 
Its detailed relations are as follows :—Its outer surface rests against the inner aspect 
of the body of the mandible above the mylohyoid ridge. — Its ¢nner surface is in contact 
with the genioglossus and the hyoglossus muscles, as well as with Wharton’s duct, which 
runs forwards between the gland and the muscles. e/ow, it rests on the mylohyoid, and 
at its posterior part on the deep process of the submaxillary gland; whilst its upper 
