THE CRANIAL OR ENCEPHALIC NERVES. 847 



stemo-maxillaris or sterno-mastoideus of Solipe.ls. These two muscular fasciculi are, other- 

 wise, closely attached to each otiier, if not cuufouuded near their origin at the anterior pro- 

 longation of the sternum. 



Lastly, the hypoglossal nerve, before crossing the pneumogastric, coiunmnicates with the 

 first cervical by a considerable brunch ; lower, it gives oflf a long raniuscuJe that descends on 

 the carotid artery. 



Pk;.— We need not refer to the olfactory, optic, or motores oeulorum, neither to the glosso- 

 pharynijeal, as what has been Siiid abf)ut tiiem in Solipeds holds good in this animal. 



Trigeminal nerue.— This also divides into tiiree principal branches. 'J he palpebro-nasal 

 ramusoule of the ophthalmic branch, anastomoses with a motor nerve of the eye on the deep 

 face of the external rectus muscle. The superior maxillary nerve leaves the cranium by the 

 great sphenoidal slit, and immediately enters the superior dental foramen ; its orbital course is 

 therefore very sliort. 



Its spheno -palatine branch passes at once below the alveolar tuberosity, where it divides 

 into several ramuscules: one, entering the palatine fissure, forms the posterior palatine nerve; 

 the others pass into the palatine arch at various distances, to constitute the middle palatine 

 nerves; some of them even enter the palatine canal with the anterior palatine or palafo-labial 

 nerve- 

 Facial.— Benenth the paroti<l glami, this divides into several branches, of which there are 

 thne principal. One is directed upwards, and passes in front of the ear ; this is the smallest. 

 The second proceeds forward, crojses the masseter near the zygomatic process, unites with the 

 inferior branch, and is expended among the suborbital ramuscules of the superior maxillary. 

 The third passes downward and forward, under the parotid gland, arrives in the intermaxillary 

 space, is inflected in front of the masseter to become superficial, and terminates with the 

 middle branch. Towards the maxillo-Iabialis muscle, this inferior branch gives off a ramuscule 

 to the lower lip. 



Pneumogastric. — This joins the sympathetic near the upper third of the neck, and at its 

 point of union offers a greyish enlargement resembling the gangliform plexus of Man. As far 

 as the origin of the oesophageal nerves, the pneumogastric of the Pig resembles that of the 

 Horse. The latter is voluminous, and does not divide into two branehes immediately beyond 

 the bronchial plexus, but at some distance from it. Numerous anastomoses exist between the 

 two cesoiihageal nerves — superior and inferior. At their termination they differ much from 

 each other in volume; the inferior is very small, and terminates on the anterior face of the 

 stomach; the superior, much laiger, partly remains at the stomach, and partly crosses the 

 small curvature of that viscus to enter the solar plexus. 



Spinal accessory. — This nerve commences and terminates as in Solipeds. After being 

 inflected backward on the anterior border of the mastoido-humeralis, it divides into two 

 ramuscules — a deep and superficial. Tlie first is confounded with a cervical nerve, near the 

 intervertebral foramen through which the latter passes ; the second goes to the trapezius 

 muscle, in which it is expended. 



Near the base of the tongue, the hypoglossal gives off a filament that passes to tlie genio- 

 hyoideus muscle. 



Carnivora. — In these animals the majority of the cranial nerves do not offer any important 

 differences. We will, therefore, say nothing concerning the first two pairs, or of the motives 

 oeulorum, spinal accessory, and glosso-piiaryugeal, except that tlie motor nerves of the eye are 

 mixed with the filament of the ophthalmic branch among the muscles of the orbit. 



Trigeminal nerve. — When the branch constituting the superficial temporal nerve, reaches 

 the posterior border of the maxilla, it divides into several ramuscules; one portion lies beside 

 the middle branch of the facial, the other accompanies the anterior auricular nerve by becoming 

 intimately united to it. We have also found, in the Dog, a branch that is detached from the 

 inferior maxillary, almost immediately after its exit from the cranium. It descends into the 

 intermaxillary space, in company with the facial artery. At the posterior border of the mylo- 

 hyoideus muscle it separates into two ramuscules : one is applied to tliat muscle, and follows 

 it to near the symphysis of the jaw ; the other is inflected outwaids and upwards, in front of 

 the mas.^eter muscle, and joins the inferior branch of the facial. Owing to this arrangement, 

 each of the branches of the facial is provided with a sensitive ramuscule from the fiftli pair. 



The lingual nerve furnishes vaso-motor and excito-secretory nerves to the submaxillary 

 and sublingual glands, as is shown in Fig. 461, b<'rrowed from Bernard. 



Facial, — At its exit from the external auditory hiatus, it divides into four branches, three 

 of which appear to form its termination. The first — the smallest — is directed downwards 

 across the parotid gland, and constitutes the cervical ramuscule. The other three are dis- 

 tinguished as superior, middle, and inferior. 



