The anterior or large palatine nerve descends from the ganglion through the posterior palatine canal, and emerges at the posterior palatine foramen. It then passes forwards in the substance of the hard palate to which it is distributed, and communicates with the naso-palatine nerve. While in the posterior palatine canal, this nerve gives off several branches (inferior nasal), which enter the nose through openings in the palate bone, and are distributed to the middle and inferior meatus, inferior spongy bone, and antrum.

The middle or external palatine nerve descends externally to the preceding to the posterior palatine foramen, and distributes branches to the tonsil, soft palate, and uvula.

The posterior or small palatine nerve, quits the other nerves to enter a distinct canal, from which it emerges by a separate opening behind the posterior palatine foramen. It is distributed to the hard palate and gums near the point of its emergence, and also to the tonsil, soft palate, and uvula.

The internal branches are the superior nasal and naso-palatine. The superior nasal nerves, four or five in number, enter the nasal fossa through the sphenopalatine foramen, and are distributed to the mucous membrane of the superior meatus, and superior and middle spongy bone.

The naso-palatine nerve (Scarpa) enters the nasal fossa with the nasal nerves, and crosses the roof the nares to reach the septum, to which it gives filaments. It then curves downwards and forwards to the naso-palatine canal, and passes through that canal to the palate, to which and to the papilla behind the incisor teeth it is distributed. This nerve was described by Cloquet as uniting with its fellow in the naso-palatine canal and constituting the naso-palatine ganglion. The existence of this ganglion is disputed.

The posterior branches are the Vidian or pterygoid nerve, and the pharyngeal. The Vidian nerve passes directly backwards from the spheno-palatine ganglion, through the pterygoid or Vidian canal, to the foramen lacerum basis cranii, where it divides into two branches, carotid and petrosal. The carotid branch (n. petrosus profundus) crosses the foramen lacerum, surrounded by the cartilaginous substance which closes that opening, and enters the carotid canal to join the carotid plexus. The petrosal branch (n. petrosus superficialis major) enters the cranium through the foramen lacerum basis cranii, piercing the carti laginous substance, and passes backwards beneath the Gasserian ganglion and dura mater, imbedded in a groove on the anterior surface of the petrous bone, to the hiatus Fallopii. In the hiatus Fallopii it receives a branch from Jacobson's nerve, and terminates in the intumescentia gangliformis of the facial nerve.

The pharyngeal nerve is a small branch which passes backwards through the pterygo-palatine canal with the pterygo-palatine artery, to be distributed to the inucous membrane of the Eustachian tube and neighboring part of the pharynx.

The OTIC GANGLION (Arnold's) is a small oval-shaped and flattened ganglion, lying against the inner surface of the inferior maxillary nerve, close to the foramen ovale; it is in relation, externally, with the trunk of that nerve, just at the point of union of the motor root; internally it rests against the cartilage of the Eustachian tube and tensor palati muscle; and posteriorly is in contact with the arteria meningea media. It is closely adherent to the internal pterygoid nerve, and appears like a swelling of that branch.

The branches of the otic ganglion are six in number; two of distribution, and four of communication.

1 Guido Guidi Latinized into Vidus Vidius, was Professor of Anatomy and Medicine in the College of France in 1542. His work is posthumous, and was published in 1611. 2 Frederick Arnold, "Dissertatio Inauguralis de Parte Cephalicâ Nervi Sympathetici." Heidelberg, 1826; and "Ueber den Ohrknoten," 1828.

The branches of distribution are, a small filament to the tensor tympani muscle, and one or two to the tensor palati.

The branches of communication are, one or two filaments from the inferior maxillary nerve (short root); one or two filaments from the auriculo-temporal nerve; filaments from the nervi molles of the arteria meningea media, and the nervus petrosus superficialis minor (long root). The latter nerve ascends from the ganglion to a small canal situated between the foramen ovale and foramen spinosum, and passes backwards on the petrous bone to the hiatus Fallopii, where it divides into two filaments. One of these filaments enters the hiatus and joins the intumescentia gangliformis of the facial; the other passes to a minute foramen nearer the base of the petrous bone, and enters the tympanum, where it communicates with a branch of Jacobson's nerve.

The SUBMAXILLARY GANGLION is a small round or triangular ganglion situated on the submaxillary gland, in close relation with the gustatory nerve, and near the posterior border of the mylo-hyoideus muscle.

Its branches of distribution, six or eight in number, divide into many filaments, which supply the side of the tongue, the submaxillary gland, sublingual gland, and Wharton's duct.

Its branches of communication are, two or three from and to the gustatory nerve; one from the chorda tympani; two or three which form a plexus with branches of the hypoglossal nerve; and one or two filaments which pass to the facial artery, and communicate with the nervi molles from the cervical portion of the sympathetic.

CAROTID PLEXUS.-The ascending branch of the superior cervical ganglion enters the carotid canal with the internal carotid artery, and divides into two branches, which form several loops of communication with each other around the artery. These branches, together with those derived from the carotid branch of the Vidian, constitute the carotid plexus. They also form frequently a small gangliform swelling at the under part of the artery, which is called the carotid ganglion. The latter, however, is not constant. The continuation of the carotid plexus onwards with the artery by the side of the sella turcica, is the cavernous plexus.

The carotid plexus is the centre of communication between all the cranial ganglia, and, being derived from the superior cervical ganglion, between the cranial ganglia and those of the trunk; it also communicates with the greater part of the cerebral nerves, and distributes filaments with each of the branches of the internal carotid, to accompany those branches to their ultimate ramifications. The branches which accompany the anterior cerebral artery at each side, unite upon the anterior communicating artery, and, according to Ribes, form a small ganglion, the ganglion of Ribes. The existence of this ganglion is disputed.

The ophthalmic ganglion communicates with the plexus by means of the long branch which reaches it from the cavernous plexus. The spheno-palatine joins the plexus by means of the carotid branch of the Vidian. The submaxillary ganglion is brought into connexion with it by means of the otic ganglion, and the otic ganglion by means of the tympanic nerve and Vidian.

It communicates with the third nerve in the cavernous sinus, and through the ophthalmic ganglion; frequently with the fourth in the formation of the nerve of the tentorium; with the Gasserian ganglion; with the ophthalmic division of the fifth in the cavernous sinus, and by means of the ophthalmic ganglion; with the superior maxillary, through the spheno-palatine ganglion; and with the inferior maxillary, through the otic ganglion. It sends two branches directly

to the sixth nerve, which unite with it as it crosses the cavernous sinus; it communicates with the facial and auditory nerve, through the medium of the petrosal branch of the Vidian; and with the glosso-pharyngeal by means of two filaments to the tympanic nerve.

CERVICAL PORTION OF THE SYMPATHETIC NERVE.

The Superior cervical ganglion is long and fusiform, of a reddish-gray color, smooth, and of considerable thickness, extending from within an inch of the carotid foramen in the petrous bone to opposite the lower border of the third cervical vertebra. It is in relation, in front, with the sheath of the internal carotid artery and internal jugular vein; and, behind, with the rectus anticus major muscle.

Its branches are divisible into superior, inferior, external, and internal; to which may be added, as proper to this ganglion, anterior.

The superior (carotid nerve) is a single branch which ascends by the side of the internal carotid, and divides into two branches; one lying to the outer, the other to the inner side of that vessel. The two branches enter the carotid canal, and, by their communications with each other and with the carotid branch of the Vidian, constitute the carotid plexus.

The inferior or descending branch, sometimes two, is the cord of communication with the middle cervical ganglion.

The external branches are numerous, and may be divided into two sets; those which communicate with the glosso-pharyngeal, pneumogastric, and hypoglossal nerve; and those which communicate with the first four cervical nerves.

The internal branches are three in number: pharyngeal, to assist in forming the pharyngeal plexus; laryngeal, to join the superior laryngeal nerve and its branches; and, superior cardiac nerve, or nervus superficialis cordis.

The anterior branches accompany the external carotid artery with its branches, around which they form plexuses, and here and there small ganglia; they are named, from the softness of their texture, nervi molles, and, from their reddish hue, nervi subrufi. The branches accompanying the facial artery are conducted by that vessel to the submaxillary ganglion, and those which accompany the internal maxillary artery reach the otic ganglion through the medium of the arteria meningea media.

The Middle cervical ganglion (thyroid ganglion) is small, and sometimes wanting. It is situated opposite the fifth cervical vertebra, and rests against the inferior thyroid artery. This relation is so constant, as to have induced Haller to name it the "thyroid ganglion."

Its superior branch, or branches, ascend to communicate with the superior cervical ganglion.

Its inferior branches descend to join the inferior cervical ganglion; one of these frequently passes in front of the subclavian artery, the other behind it. Its external branches communicate with the fifth and sixth cervical nerve. Its internal branches are filaments which accompany the inferior thyroid artery, inferior thyroid plexus; and the middle cardiac nerve, nervus cardiacus magnus.

The Inferior cervical ganglion (vertebral ganglion) is much larger than the preceding, and constant in its existence. It is of a semilunar form, and situated on the base of the transverse process of the seventh cervical vertebra, immediately behind the vertebral artery; hence its designation "vertebral ganglion."

1 Panizza, in his "Experimental Researches on the Nerves," denies this communication, and states very vaguely that "they are merely lost and entwined around it."-Edinburgh Medical and Surgical Journal, Jan. 1836.

Its superior branches communicate with the middle cervical ganglion. The inferior branches pass some before and some behind the subclavian artery, to join the first thoracic ganglion.

The external branches consist of two sets; one which communicates with the sixth, seventh, and eighth cervical, and first dorsal nerve, and one which accompanies the vertebral artery along the vertebral canal, forming the vertebral plexus. The plexus sends filaments to all the branches given off by that

THE GREAT SYMPATHETIC NERVE. 36. The cavity of the cranium. 34. The globe of the eye. 33. The septum of the nose. 32. The incisor teeth. 31. The submaxillary gland. 30. The larynx. 29. The heart. 28. The left lung.

The coeliac axis. 27. The ascending vena cava. 26. The kidney. 25. The crista of the ilium. 24. The pubes. 23. The bladder. 22. The rectum. 1. Plexus on the carotid artery in the carotid foramen. 2. Sixth nerve, (abducens.) 3. First branch of the fifth, or ophthalmic nerve. 4. Nasopalatine nerve on the septum narium, connecting Meckel's ganglion with Cloquet's in the incisive foramen. 5. Immediately above the figure is the recurrent branch, pterygoid, or Vidian nerve, dividing into the carotid and petrosal branches. 6. Anterior or large palatine branch of Meckel's ganglion. 7. Gustatory nerve joined by the chorda tympani. S. The portio dura of the seventh pair, or facial nerve. 9. The superior cervical ganglion. 10. The middle cervical ganglion. 11. The inferior cervical ganglion. 12. The rocts of the great splanchnic nerve, arising from the thoracic ganglia. 13. The lesser splanchnic nerve. 14. The renal plexus. 15. The solar plexus. 16. The mesenteric plexus. 17. The lumbar ganglia. 18. The sacral ganglia. 19. The vesical plexus. 20. The rectal plexus. 21. The lumbar plexus, (cerebrospinal.)]

artery, and communicates in the cranium with the filaments of the carotid plexus accompanying the branches of the internal carotid artery.

The internal branch is the inferior cardiac nerve, nervus cardiacus minor..

CARDIAC NERVES.-The cardiac nerves are three in number at each side, namely, superior, middle, and inferior.

The Superior cardiac nerve (nervus superficialis cordis) proceeds from the lower part of the superior cervical ganglion; it descends the neck behind the common carotid artery and parallel with the trachea, crosses the inferior thyroid artery, and running by the side of the recurrent laryngeal nerve, enters the chest. The nerve of the right side passes either in front of or behind the subclavian artery and along the posterior aspect of the arteria innominata to the deep cardiac plexus. The left superior cardiac nerve runs by the side of the left carotid artery, and crosses the arch of the aorta to the superficial cardiac plexus.

In its course it receives branches from the pneumogastric nerve, and sends filaments to the thyroid gland and trachea.

The Middle cardiac nerve (nervus cardiacus magnus) proceeds from the middle cervical ganglion, or, in its absence, from the cord of communication between the superior and inferior ganglion. It is the largest of the three nerves, and lies parallel with the recurrent laryngeal. At the root of the neck it divides into several branches, which pass some before and some behind the subclavian artery, communicates with the superior and inferior cardiac, pneumogastric and recurrent nerve, and descends to the bifurcation of the trachea, to join the deep cardiac plexus.

The Inferior cardiac nerve (nervus cardiacus minor) arises from the inferior cervical ganglion, communicates with the recurrent laryngeal and middle cardiac nerve, and descends to the front of the bifurcation of the trachea, to the deep cardiac plexus.

The SUPERFICIAL CARDIAC PLEXUS is situated immediately beneath the arch of the aorta, and in front of the right pulmonary artery. It receives the superior cardiac nerve of the left side and the inferior cardiac branch of the left pneumogastric nerve, both of which cross the arch of the aorta between the left phrenic and pneumogastric nerve. It receives besides several filaments from the deep cardiac plexus, and sometimes a cardiac branch from the right pneumogastric nerve. Connected with the plexus is a small ganglion (sometimes wanting), the cardiac ganglion of Wrisberg, which lies close to the right side. of the fibrous cord of the ductus arteriosus. The superficial cardiac plexus gives off filaments which pass along the front of the left pulmonary artery to the root of the left lung, where they communicate with the anterior pulmonary plexus; while the principal part of the plexus descends in the groove between the pulmonary artery and aorta to the anterior longitudinal sulcus of the heart, where it comes into relation with the anterior coronary artery, and becomes the anterior coronary plexus. At the base of the heart, the anterior coronary plexus receives several filaments from the deep cardiac plexus. Its branches are distributed to the substance of the heart in the course of the left or anterior coronary artery.

The DEEP or GREAT CARDIAC PLEXUS is situated on the bifurcation of the trachea, above the right pulmonary artery and behind the transverse portion of the arch of the aorta. It receives, on the right side, the three cardiac nerves of the sympathetic of the same side, and the cardiac branches of the right pneumogastric and right recurrent nerve. On the left side it receives the middle and inferior cardiac nerves of the sympathetic of the left side; the cardiac branches of the left pneumogastric (excepting the inferior), and several cardiac branches from the left recurrent nerve. In other words, it receives all the cardiac filaments of the sympathetic, pneumogastric, and recurrent nerves, with the exception of the left superior cardiac of the sympathetic (nervus superficialis cordis) and the inferior cervical cardiac of the left pneumogastric, these two nerves being destined to the superficial cardiac plexus.

The branches of the deep cardiac plexus, proceeding from its right and left division, pass downwards to join the coronary arteries, and outwards to the pulmonary plexuses.