158 DISSECTION OF THE DOG 



gland. The following are its superficial branches : (1) The auriculo-palpebral 

 nerve (n. auriculo-palpebraUs), which divides into a temporal ramus (ramus 

 temporalis), supplying the front part of the ear, and a zygomatic ramus (ramus 

 zygomaticus). The latter crosses the zygomatic arch, furnishes twigs to both 

 eyehds, and ends on the side of the nose, where it arrives by curving round the 

 medial side of the eye. (2) The dorsal buccal nerve (n. buccaUs dorsaUs) crosses 

 the surface of the masseter muscle and ends in the upper lip ; while (3) the 

 ventral buccal nerve (n. buccalis ventrahs) follows the ventral border of the 

 muscle and ends in the lower lip. A considerable amount of intercommunica- 

 tion takes place between branches of the two buccal nerves. (4) The smallest 

 superficial branch of the facial nerve — the cervical branch (ramus colli) — pierces 

 the parotid gland and joins the superficial cervical branch of the second spinal 

 nerve. 



N. TEiGBMiNus. — The trigeminal, or fifth cerebral nerve, has not long left 

 the brain before it divides into three parts — the ophthalmic, maxillary, and 

 mandibular nerves — all of which supply branches which should be sought at 

 this stage of the dissection. 



N. ophthalmicus. — Two branches of the ophthalmic nerve become superficial 

 about the eye : (1) Th.efro7ital nerve (n. frontalis) leaves the orbit by bending 

 round the orbital band — a fibrous cord stretching from the zygomatic to the 

 frontal bone — and is expended in the upper eyelid and its neighbourhood, 

 where it assists in the formation of the anterior auricular plexus ; (2) the 

 infratrochlear 7ierve (n. infratrochlearis) appears medial to the eye. 



N. maxillaris. — The maxillary nerve furnishes four branches — two small 

 and two large — to the face : (1) The lachrymal nerve (n. lacrimalis) leaves the 

 orbit lateral to the point of exit of the frontal nerve, and plays a part in the 

 formation of the anterior auricular plexus ; (2) the zygomatic nerve (n. zygoma- 

 ticus) is quite small, emerges from the orbit close to the lateral commissure of 

 the eyelids and ends mainly in the lower eyelid ; (3) the two large infraorbital 

 nerves (nn. infraorbitales) leave the foramen of that name and spread out in the 

 substance of the upper lip and nose. They will receive fiu-ther attention at a 

 later stage. 



N. mandibularis. — The mandibular nerve contributes three branches to the 

 face : (1) The superficial temporal nerve (n. temporalis superficialis) bends round 

 the border of the mandible and divides into auricular and temporal 

 branches ; (2) the mental nerve (n. mentalis) leaves the foramen of the same 

 name and supplies the lower lip ; (3) the buccinator nerve (n. buccinatorius) 

 becomes visible at the oral border of the masseter muscle and ends in the cheek 

 and lower lip, some of its branches joining the plexus formed by the buccal 

 nerves derived from the seventh cerebral nerve. 



A. FACIALIS. — The facial artery will be found in a groove bounded by the 

 masseter and digastric muscles. Its branches are the inferior labial artery 

 (a. labiahs inferior), the angular artery of the nnouth (a. angularis oris), and the 



