THE STOMACH. 



467 



tendinons centre of the diaphragm by connective tissue. Tho posterior fare lies against the 

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

 sternal region. The lesser, superior, or concave curvature partly corresponds t<^ the lesser 

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

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

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



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

 the mucous membrane into polyht dral 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, 

 include.! one within the otiier, by secondary and successively decreasing septa. The principal 

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

 while their faces are studded wiili minute, blunt, or pointed papillae. The secondary septa 

 also show similar prolongations; and these 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 

 BO 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, and 

 needles or pins — often fixed in the inter- 

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

 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 iufundibulum of the 

 cardia by a remarkable groove (or chan- 

 nel) — the (esophageal — which will be de- 

 scribed separately, as it does not properly 



Fig. 270. 



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, (Esophageal groove ; Y, its pos- 

 terior lip; Z, its anterior lip; V, opening com- 

 municating with the reticulum and uin;isum ; R, 

 spleen ; O, opening between the rumen and reti- 

 culum. 



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 memh'rane sends a prolongation into each of the septa of the alveoli, 

 and into each of the conical papiilte on these 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 the Camel, the reticidum 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 a;sophageal furrow 

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

 middle portion. 



CEsoPHAGEAL 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 

 the reticulum from the cardia to the entrance of the omasum ; commencing in the rumen, it 

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

 in length, this demi-canal is directed from 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 neither meet nor become confounded with each other 



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



