cles. The two internal pterygoids raise it; the two external pterygoids stretch it transversely; the two palato-pharyngei or pharyngo-staphylini, and the two constrictores isthmi faucium or glosso-staphylini carry it downwards. The last four muscles form the pillars of the fauces;the first two the posterior pillars; and the last two the anterior; between which are situate the tonsil glands or amygdala, which are not really glandular, but composed of a congeries of mucous follicles.

2. The pharynx and œsophagus constitute a muscular canal, which forms the medium of communication between the mouth and stomach, and conveys the food from the former of these cavities to the latter.

The pharynx has the shape of an irregular funnel, the larger opening of the funnel looking towards the mouth and nose; the under and smaller end terminating in the oesophagus. Into its upper part, the nasal fossæ, Eustachian tubes, mouth, larynx, and oesophagus open. It is inservient to useful purposes in the production of voice, respiration, audition, and digestion; and extends from the basilary process of the occipital bone, to which it is attached, as far as the middle part of the neck. Its transverse dimensions are determined by the os hyoides, larynx, and pterygo-maxillary apparatus, to which it is attached. It is lined by a mucous membrane, less red than that which lines the mouth, but more so than that of the esophagus, and the rest of the digestive tube; and it is remarkable for the developement of its veins, which form a very distinct network. Around this is the muscular layer, the circular fibres of which are often divided into three muscles-superior, middle, and inferior constrictors. The longitudinal fibres form part of the stylo-pharyngei and palato-pharyngei muscles. The pharynx is raised by the action of the last two muscles, as well as by all those that are situate between the lower jaw and os hyoides, which cannot raise the latter without, at the same time, raising the larynx and pharynx. These muscles are:-mylo-hyoideus, genio-hyoideus, and the anterior belly of the digastricus.

The esophagus is a continuation of the pharynx; and extends to the stomach, where it terminates. Its shape is cylindrical, and it is connected with the surrounding parts by loose and extensible areolar tissue, which yields readily to its movements. On entering the abdomen, it passes between the pillars of the diaphragm, with which it is intimately united. The mucous membrane lining it is pale, thin, and smooth; forming longitudinal folds, well adapted for favouring the dilatation of the canal. Above, it is confounded with that of the pharynx; but below, it forms several digitations, terminated by a fringed extremity, which is free in the cavity of the stomach. It is well supplied with mucous follicles. The muscular coat is thick; its texture is denser than that of the pharynx,-and cannot, like it, be separated into distinct muscles, but consists of circular and longitudinal fibres, the former of which are more internal, and very numerous, the latter external and less numerous. Fig. 217 exhibits the situation and arrangement of the two sets of fibres.

3. The stomach is situate in the cavity of the abdomen, and is the most dilated portion of the digestive tube. It occupies the epigastric region, and a part of the left hypochondre. Its shape has been com

pared, not inappropriately, to that of the bag of a bag-pipe. It is capable of holding, in the adult male, when moderately distended, about three pints. The left half of the organ has always much greater

A, A. Anterior surface. B. Enlargement at lower part. D. Cardiac orifice. E. Commencement of duodenum. F and C. Coronary vessels. H. Omentum.

dimensions than the right. The former has been called the splenic portion, because it rests upon the spleen; the latter the pyloric portion, because it corresponds to the pylorus. The inferior border of the stomach, which is convex, is termed the great curvature or arch; the superior border, the lesser curvature or arch. The two orifices are the œsophageal, cardiac, or upper orifice, formed by the termination of the oesophagus; and the intestinal, pyloric or inferior orifice, which communicates with the small intestine.

The three coats that constitute the parietes of the stomach, are arranged in a manner the most favourable for permitting variation in the size of the organ. The outermost or peritoneal coat consists of two laminæ, which adhere but slightly to the organ, and extend beyond it, where they form the epiploons or omenta, the extent of which is in an inverse ratio to the degree of distension of the stomach. The omentum majus or gastro-colic epiploon is the part that hangs down from the stomach in Fig. 218.

The mucous or lining membrane is of a whitish, marbled, red appear

ance, having a number of irregular folds, situate especially along the inferior and superior margins of the organ. These folds are evident, also, at the splenic extremity; and are more numerous and marked, the more the stomach is contracted. They are radiated towards the cardiac,-longitudinal towards the pyloric, orifice. This membrane, like every other of the kind, exhales an albuminous fluid from a multitude Fig. 219. Fig. 220.

Vertical and Longitudinal Section of Stomach and
Duodenum.

1. Esophagus; upon its internal surface, the plicated arrangement of cuticular epithelium shown. 2. Cardiac orifice of stomach, around which the fringed border of cuticular epithelium is seen. 3. Great end of stomach. 4. Its lesser or pyloric end. 5. Lesser curve. 6. Greater curve. 7. Dilatation at lesser end of stomach which received from Willis the name of antrum of pylorus. This may be regarded as the rudiment of a second stomach. 8. Ruga of the stomach formed by mucous membrane: their longitudinal direction is shown. 9. Pylorus. 10. Oblique portion of duodenum. 11. Descending portion. 12. Pancreatic duct, and ductus communis choledochus, close to their termination. 13. Papilla upon which ducts open. 14. Transverse portion of duodenum. 15. Commencement of jejunum. In interior of duodenum and jejunum, the valvulæ conniventes are seen. (Wilson.)

Section of a piece of Stomach not far from Pylorus.

1. Magnified about three diameters. 2. A few of the glands with their racemiform ends distended with fluid, magnified about 20 diameters. (Wagner.)

of delicate villi, which are as perceptible in the stomach as in any part of the digestive tube. It contains, likewise, many follicles, which are especially abundant in the pyloric portion. (Fig. 220.) Several, also, exist in the vicinity of the cardiac orifice, but in the rest of the membrane they are few in number. When examined with a magnifying glass, the internal or free surface presents a peculiar honeycomb appearance, produced by shallow polygonal depressions or cells as represented in the marginal figure. (Fig. 223.) The diameter of these cells varies from th to 7th of an inch; but, near the pylorus, it is as much as th of an inch. In the bottom of the cells, minute openings are visible, which are the orifices of perpendicular glands embedded, side by side, in bundles in the substance of the mucous membrane, and composing nearly the whole structure. These tubular follicles vary in

'Dr. Sprott Boyd, Edinb. Med. and Surg. Journal, vol. xlvi.

Fig. 221.

length from one-fourth of a line to nearly a line. They are longer and more closely set towards the pylorus than elsewhere, their length being equal to the thickness of the mucous membrane of the stomach, which varies.

The office of these tubular follicles, it has been thought, is to secrete the gastric fluid, during digestion; for in the intervals they are at rest. They are formed by inflections of basement membrane, with cylindrical epithelium resting upon it. One of them is represented in the marginal figure, which exhibits the nucleated cells at the bottom of the follicle; becoming more and more developed as they approach the free surface. These cells prepare the gastric fluid, and ultimately burst and discharge it to become mixed with the aliment in the stomach.

Besides these glands or follicles, small opaque-white sacculi, resembling Peyer's glands, are met with, which Tubular Follicle of are filled with minute cells and granules. They are Pig's Stomach. (After Wasmann.) situate chiefly along the lesser curvature of the stomach

beneath the lining membrane; are probably concerned in the separation of some secretion from the blood, and when filled burst, like other secreting cells, and discharge their contents into the stomach.'

The pylorus, or the part at which the stomach terminates in the small intestine, is marked,

externally, by a manifest narrowness, as at 9, Fig. 219. Internally, the mucous membrane forms a circular fold, which has been called valve of the pylorus, between the two laminae of which, a dense, fibrous tissue exists. This has been called by some authors, pyloric muscle.

The muscular coat, which is exterior to the mucous coat,-as in the parts of the digestive tube already described,

Fig. 224.

consists of several laminæ Front View of Stomach, distended by flatus, with Peritoneal

of fibres, less distinct than
those of the oesophagus;
or rather more irregularly
distributed. The most
common opinion is, that
there are three lamina:-
an external, longitudinal series; a middle transverse or circular stratum;
and an inner stratum with fibres running obliquely. Both circular and
longitudinal fibres are separated from each other, especially in the
splenic portion, the separation augmenting or diminishing with the
varying size of the stomach..

tremity. 3. Lesser or pyloric extremity. 4. Duodenum. 5, 5.
A portion of the peritoneal coat turned back. 6: A portion of
the longitudinal fibres of the muscular coat. 7. Circular fibres
of the muscular coat. 8. Oblique muscular fibres, or muscle of
where its peritoneal coat has been removed.
Gavard. 9. A portion of the muscular coat of the duodenum,

1. Anterior face of esophagus. 2. Cul-de-sac, or greater ex

The blood-vessels and nerves of the stomach are more numerous than those of any other organ of the body. The arteries are disposed along the curvatures. On the lesser curvatures are,-coronaria ventriculi, and the pyloric branch of the hepatic artery; on the great curvature, the right gastro-epiploic, which is a branch of the hepatic; and the left gastro-epiploic, a branch of the splenic. The splenic artery, too, furnishes numerous branches to the left cul-de-sac behind. These are called vasa brevia or gastro-splenic. The nerves of the stomach are of two kinds. Some proceed from the great sympathetic, from the coeliac plexus, and accompany the arteries through all their ramifications. Others are furnished by the pneumogastric or eighth pair; the two nerves of which surround the cardiac orifice like a ring. The number of the nerves, and the variety of sources whence they are derived, explain the great sympathetic influence exerted upon the stomach by affections of other parts of the system. It sympathizes, indeed, with