tongue, and are of a glandular structure. They are arranged in two rows. The mucous membrane is not closely adherent to them, as it is to the true papillæ.

Fig. 54.

PILLE.-1. The raphé, which in some tongues bifurcates on the dorsum of the organ, as in the figure. 2, 2. The lobes eminences on this part of the organ, and near its tip, are the papillæ fungiformes. The smaller papillæ, among which the former are dispersed, are

of the tongue. The rounded

formes. 3. The tip of the

The true papillæ are divided into three classes, as follows:

The calyciform consist of two rows which are arranged in the form of the letter V. There are from six to eight in each row. They are situated on the posterior part of the tongue. Each papilla is attached to the centre of a cup-like depression by its small extremity, leaving its large extremity free, and on a level with the surface of the tongue. At the junction of the two rows behind. is a deep depression, called the "foramen cæcum." It has opening into it several mucous follicles. Sometimes a papilla is found in the place of it.

The fungiform are found near the sides and tip of the tongue. They are of a reddish color, and much smaller than the preceding. They are best seen when a sapid substance is applied to the living tongue, as they then become distended.

The conical papillae are diffused the papillæ conica, and fili- over the greater part of the dorsum tongue. 4, 4. Its sides, on of the tongue. They are inclined which are seen the lamellated backwards, which becomes very ap and fringed papillæ. 5, 5. The V-shaped row of papilla parent when the tongue is rubbed calyciformes. 6. The fora- from behind forwards, especially in glands of the root of the some of the lower animals. They are tongue. 8. The epiglottis. of a whiter color than the others. 9, 9. The fræna epiglottidis. 10, 10. The greater cornua of the os hyoides.

men cæcum. 7. The mucous

The papillæ are very vascular, and are supplied with filaments from the fifth and glosso-pharyngeal nerves.

The FAUCES, Fig. 55, is the space between the mouth and

the pharynx. It is bounded above by the soft palate, on each side by the anterior and posterior half-arches of

MEDIAN SECTION OF THE NOSE, MOUTH, PHARYNX, AND LARYNX.-a. Septum of the nose; below it is the section of the hard palate. b. The tongue. c. Section of velum pendulum palati. d, d. Lips. u. Uvula. r. Anterior half-arch or pillar of fauces. i. Posterior half-arch. t. Tonsil. p. Pharynx. h. Hyoid bone. k. Thyroid cartilage. n. Cricoid cartilage. 8. Epiglottis. v. Glottis. 1. Posterior opening of nares. 3. Fauces. 4. Superior opening of larynx. 5. Passage into œsophagus. 6. Mouth of right Eustachian tube.

the palate and the amygdaloid fossa, which contains the tonsil, and below by the base of the tongue. Its parietes are all movable, and contain muscular structure. The anterior half-arch, Fig. 55, r, on each side is formed by the palato-glossus muscle and the mucous membrane reflected around it. It has nearly a vertical direction transversely. The posterior halfarch, Fig. 55, i, is formed by the palato-pharyngeus muscle. Its direction is downwards, backwards, and outwards. It projects inwards more than the anterior. Between these halfarches is the amygdaloid fossa. It is of a triangular shape with the apex above. The lower part or base of it corresponds very nearly with the angle of the lower jaw. Its

outer wall is formed by the superior constrictor of the pharynx and the pharyngeal aponeurosis, by which the excava tion containing the tonsil is separated from the internal carotid artery.

The tonsil, Fig. 55, t, is composed of a number of follicles collected into a group. Its internal surface is perforated by foramina which communicate with these follicles. A single foramen may open into a cell or cavity with which several follicles communicate. In excising the tonsil when enlarged, there can be no danger of wounding the internal carotid if the incision be not made deeper than on a level with the halfarches. Nor is there any danger of injuring the same artery in opening abscesses of the tonsil if the bistoury be not carried into it too far in a posterior direction, as the artery lies outside and between the tonsil and the vertebræ, on the rectus capitis anticus major. Abscesses of the tonsil almost always open internally on account of the resistance offered by the pharyngeal aponeurosis. Mucus sometimes collects and becomes inspissated in the follicles, and when discharged gives rise to the idea that tuberculous matter has been expectorated. The tonsil is supplied principally by the palatine branches of the pharyngeal arteries. These arteries sometimes attain a considerable size in enlargements of the tonsils, and consequently may give rise to quite a profuse hemorrhage when they are excised.

The PHARYNX, Fig. 55, p, is the third division of the alimentary canal. It extends from the cuneiform process of the occipital bone to a point opposite the fifth cervical vertebra. It communicates with the tympana, nasal fossa, mouth, larynx, and œsophagus. Its position and relation to contiguous parts render an accurate knowledge of it exceedingly important. It may be very properly considered as divided into a nasal, a faucial, and a laryngeal section. This division is not based upon its structure, but upon its relations to the parts placed in front of it. Its posterior wall corresponds to the bodies of the superior five cervical vertebræ. This sents nothing which requires to be noticed at the present time. The same is true with the lateral walls, except at the upper part, where the orifices of the Eustachian tubes are found. The pharynx has no anterior wall peculiar to itself, but is intimately associated with the nasal cavities, the fauces, and the larynx.

pre

The posterior nares open into its upper part in a vertical direction. They are each about an inch in height, half an inch in breadth, and about three-fourths of an inch from the posterior wall of the pharynx; their surface is smooth, and they are slightly expanded, which facilitates the introduction of a plug, when this becomes necessary to arrest hemorrhage, and at the same time allows the plug to slip back into the pharynx, unless it be retained by the proper means in situ. It will be observed that in plugging the posterior nares, unless the plug be adapted to their shape, the lower part of the orifice may be closed while the upper part will be left open.

The pharyngeal orifice of each Eustachian tube will be seen a short distance behind, and to the outside of the nasal orifice. It is on a plane about one-fourth of an inch above the floor of the nasal fossa. It is somewhat expanded in the shape of a funnel, which readily admits a probe, or a tube for injecting the tympanum. Quite a deep sulcus in the upper and outer part of the pharynx should be noticed. It is just behind, and separated from the Eustachian orifice by a ridge.

The SOFT PALATE and the UVULA, Fig. 55, c, u, projecting from the centre of its free border, may now be examined. It is a muscular organ, firmly attached to the posterior margin of the hard palate, and projecting backwards and downwards into the pharynx; it serves to extend the floor of the nasal fossa and roof of the mouth in this direction. It diminishes in thickness from before backwards, and assumes an arched form, with the concavity looking downwards and forwards. When elevated, it has a horizontal direction, and its free border is applied to the posterior wall of the pharynx, so as to form a septum between its upper and two lower divisions. The palate is marked on both of its surfaces in the middle by a whitish line or raphé.

The UVULA has a conical shape, varies very much in size, and consists principally of mucous membrane and areolar tissue, with a few longitudinal muscular fibres. It is pendulous, and, when not enlarged, its tip nearly touches the tongue, near the foramen cæcum. Its areolar tissue is liable to be filled with serum in inflammation of the throat, causing it to rest upon the tongue, and thus giving rise to a sense of titillation. Its weight, in these cases, may have a tendency to draw down the soft palate.

At the lower part of the faucial opening in the pharynx, are two fossa or depressions, situated between the root of the tongue and the epiglottis, and separated from each other by a fold of mucous membrane, called frænum epiglottidis. These fossæ are sometimes quite deep, and allow small bodies to lodge in them, which may give rise to irritation and spasmodic cough.

In the anterior part of the laryngeal portion of the pharynx will be noticed the epiglottis, glottis, greater cornua of the hyoid bone, posterior borders of the ale of the thyroid cartilage, arytenoid, and cricoid cartilages. The exact location of each of these bodies is deserving of particular notice. They will be considered separately in connection with the larynx. The hyoid bone seems to belong both to the tongue and the larynx. It will be described with the latter.

Before leaving the cavities just described, it would be well for the student to study them carefully in their relations to each other, as in reference to introducing the stomach tube, extracting foreign bodies from the pharynx or oesophagus, carrying an instrument into the larynx, either through the mouth or nose, opening abscesses in the pharynx, removing polypi or tumors about the posterior nares, &c.

SECT. XII.-DISSECTION OF THE PALATE.

The soft palate contains five pairs of muscles. These are exposed, and their arrangement seen by very little dissection, which may be done after the removal of the pharynx.

The palatine aponeurosis is a fibrous prolongation from the posterior margin of the hard palate. It diminishes in thickness as it descends towards the free border. It is connected with the tendons of the palatine muscles, and forms a sort of framework for the palate.

The AZYGOS UVULÆ, Fig. 57 (s), consists of two vertical fasciculi, which arise from the centre of the free border of the hard palate, and extend to the tip of the uvula. In excising the uvula, the mucous membrane should not be made tense; if it be done, the fibres of this muscle may project from the wound after the membrane has retracted.

The LEVATOR PALATI, Fig. 56 (2, 3), consists of a vertical