3G6 



THE DIGESTIVE APPARATUS IN MAMMALIA. 



border of the inferior maxilla and the transverse process of the atlas. It is 

 elongated from above to below, flattened on both sides, and divided into 

 two faces, two borders, and two extremities. 



The external face, nearly plane, is hollowed in its inferior part into a 

 longitudinal channel, which is sometimes transformed into a complete canal, 

 and lodges the jugular vein after it has traversed the gland from below 

 to its superficies. This external face responds to the parotido-auricularis 

 muscle, the subcutaneous muscle, the atloidean loop, a cervical ramification 

 of the facial nerve, and the posterior auricular vein. The internal face is 

 very uneven and moulded on the subjacent parts. It covers the guttural 

 pouch, the mastoid insertion of the small oblique muscle of the head, 

 levator humeri, stylo-hyoideus, the tuberosity on the posterior border of 

 the os hyoides, the digastricus, the tendon of the stern o-maxillaris, and 

 the submaxillary gland, which is separated from it by the thin cellulo- 

 aponeurotic layer uniting the latter muscle to the levator humeri ; also to 



Fig. 171 



MODES OF TERMINATION OF THE NERVES IN THE SALIVARY GLANDS. 



1 , 2, Branching of the nerves between the salivary cells ; 3, Termination of the 

 nerve in the nucleus ; 4, Union of a ganglion cell with a salivary cell ; 5, Varicose 

 nerve-fibres entering the cylindrical cells of the excretory ducts. 



the external carotid artery and its two terminal branches, the posterior 

 auricularis, the muscles of the jaw, and, lastly, the facial nerve, which often 

 passes through the substance of the gland. 



The anterior border of the gland is intimately united to the posterior 

 border of the maxilla ; it is related to the temporo-maxillary articulation, 

 the subzygomatic vessels and nerves, and the maxillo-muscular vessels. 

 The posterior border is thicker than the preceding, and is separated from the 

 transverse process of the atlas by the terminal aponeurosis of the levator 

 humeri, to which it is only feebly adherent : it can also be easily separated 

 from it, in order to raise the parotid and pass through the stylo-hyoideus 

 muscle, in the operation of hyo-vertebrotomy. 



The superior extremity is bifurcated, and embraces the base of the concha 

 of the ear. The inferior extremity is comprised in the angle formed by the 

 union of the jugular and glosso-facial veins. 



