THE STOMACH. 



467 



tendinous centre of the diaphragm by connective tissue. The posterior face lies against the 

 anterior extremity of the rumen. The great inferior or convex curvature occupies the supra- 

 sternal region. The lesser, superior, or concave curvature partly corresponds to the lesser 

 curvature of the omasum. The left extremity is only separated from the rumen by a fissure, 

 which lodges the inferior artery of tlie reticulum. The right extremity formp a globular 

 cul-de-sac, in relation with the base of the abomasum. 



Interior (Figs. 269, 270). — The internal surface of the reticulum is divided by ridges of 

 the mucous membrane into polyhedral cells, which, in their regular arrangement, look like a 

 honeycomb ; tliey are widest and deepest in the cul-de-sac, and become gradually smaller in 

 approaching the superior curvature. The interior of these cells is divided into smaller spaces, 

 included one within the other, by secondary and successively decreasing septa. The principal 

 septa offer on their free border a series of conical prolongations, with a rough hard summit ; 

 while their faces are studded with minute, blunt, or pointed papillsB. The secondary septa 

 also show similar prolongations ; and those on their free margin are even more developed than 

 on the chief septa. Lastly, from the 

 bottom of the cells spring up a crowd of 

 long, conical, and very pointed papillae, 

 resembling stalagmites in their arrange- 

 ment. 



It maybe noted that the foreign bodies 

 so frequently swallowed by Ruminants, 

 are usually lodged in the reticulum; 

 therefore it is that at the bottom of the 

 cells are found either small stones, at 1 

 needles or pins — often fixed in the inte 

 mediate septa — or nails, scraps of iron, et.. 

 The interior of the reticulum communi- 

 cates with the left sac of the rumen by 

 the orifice already described, and with 

 the omasum by a particular opening 

 placed near the middle of the small curva- 

 ture, though a little more to the right 

 than the left. This opening — eight or 

 ten times smaller than the preceding — is 

 connected with the infundibulum of the 

 cardia by a remarkable groove (or chan- 

 nel) — the oesophageal — which will be de- 

 scribed separately, as it does not properly 

 belong to the reticulum. 



Structure. — The serous membrane does not cover all the anterior surface of the organ, as 

 the latter adheres to the posterior face of the diaphragm. The muscular tunic is much thinner 

 than that of the paunch, and more fasciculated. The fibres pass in the same direction. The 

 corium of the mucous membrane sends a prolongation into each of the septa of the alveoli, 

 and into each of the conical papillse on tiuse septa, or to the bottom of these alveoli. The 

 stratified pavement epithelium is very thick, and its horny layer is very developed at the 

 summit of the papillae. 



In tl)e Camel, the reticulum does not form a compartment distinct from the rumen, and its 

 existence is only indicated by some deep cells in the anterior part of that cavity. The 

 entrance of the oesophagus into the rumen is oblique from left to right. The oesophageal furrow 

 Ib limited by two unequal lips, the posterior being only slightly prominent, especially in its 

 middle portion. 



(Esophageal Groove (Figs. 268, 270, 271).— This furrow is so named because it appears 

 to continue the oesophagus to the interior of the stomach. It extends on the lesser curvature of 

 tliC reticulum from the c.irdia to the entrance of the omasum ; commencing in the rumen, it 

 belonsrs to the reticulum for the remainder of its extent. Measuring from six to eight inches 

 in length, this demi-canal is directed fiom above downwards, and from left to right, between 

 two movable lips, which are fixed by their adherent border to the superior wall of the reti- 

 culum. These two lips are thickened at their free margins, which look downwards and to 

 the left. At their origin at the oesophageal infundibulum, they are thin and but slightly 

 elevated; but they become thick and salient on arriving near the orifice of the oma.sum, which 

 orifice they surround, though they neitlier meet nor become confounded with each other 



The mucous membrane covering these two lips is much corrugated outwardly and on the 



ANTERIOR VIEW OF THK OX'S STOMACH (THE AN- 

 TERIOR WALL OF THE RETICULUM HAS BEEN 

 REMOVED TO SHOW THE (ESOPHAGEAL GROOVE). 



A. (Esophagus ; B, left sac of the rumen ; C, right 

 sac ; D, reticulum ; d', interior of ditto; E, omasum ; 

 F, abomasum ; x, oesophageal groove ; Y, its pos- 

 terior lip; z, its anterior lip; v, opening com- 

 municating with the reticulum and omasum ; R, 

 spleen ; O, opening between the rumen and reti- 

 culum. 



