THE GLANDS OF THE MOUTH (GLANDULÆ ORIS).--There are five pairs of salivary glands which open into the mouth cavity. 1. The =parotid gland= (=glandula parotis=) (Fig. 65, 1; Fig. 131, 10) is flattened, rather finely lobulated, and lies ventrad of the external auditory meatus and beneath the dermal muscles. Its cranial border follows the caudal border of the masseter muscle and overlies it somewhat; its caudal border is about three centimeters caudad of the border of the masseter. Its borders are unevenly lobed. The parotid duct (=ductus parotideus=: frequently called =Stenon’s= or =Steno’s duct=) is formed by the union of several smaller ducts near the ventral end of the cranial border of the gland. It passes craniad imbedded in the fascia covering the masseter. At the cranial border of the masseter it turns inward and lies close against the mucous membrane of the mouth, so that from the inside of the mouth it appears as a white ridge on the mucosa. It opens on the inside of the cheek opposite the most prominent cusp of the last premolar tooth. Along the course of the parotid duct in some cases one or more small =accessory parotid glands= are found. 2. The =submaxillary gland= (=glandula submaxillaris=) (Fig. 65, 2, page 109, and Fig. 131, 11) is approximately kidney-shaped. Its surface is nearly smooth, the lobulations not being apparent externally. It lies ventrad of the parotid, at the caudal edge of the masseter muscle, just caudad of the angular process of the mandible. The posterior facial vein (Fig. 131, =b=) crosses its outer surface, and its cranioventral border is hidden by two lymphatic glands (Fig. 131, 12) lying at the sides of the anterior facial vein. The =submaxillary duct= (=ductus submaxillaris=, frequently called =Wharton’s duct=) leaves the inner surface of the gland and passes beneath the digastric and mylohyoid muscles and against the outer surface of the styloglossus. From the point where the styloglossus passes into the tongue the duct continues craniad close against the oral mucosa and parallel to the mandibula. It is accompanied by the duct of the sublingual, which lies at first dorsad of it and then mediad. It opens at the apex of the prominent papilla which lies at the side of the middle line at the cranial end of the floor of the mouth. 3. The =sublingual gland= is elongated and conical in form, with its base against the submaxillary, of which it appears to be a continuation. It stretches along the submaxillary duct for about one and one-half centimeters, lying between the masseter and digastric muscles. The =sublingual= duct leaves its ventral side, passes close to the submaxillary duct, at first dorsad and then mediad of it, and opens on the medial side of the apex of the same papilla with the submaxillary duct.