464 



THE DIGESTIVE APPARATUS IN MAMMALIA. 



These cavities represent a considerable mass that fills the greater part of the abdominal 

 cavity, and the medium capacity of which is not less than fifty-tive gallons ! One of them, 

 the Rumen, into which the oesophagus is inserted, constitutes nine-tenths of the total mass. 

 The other three, the Reticulum, Omasum, and Ahoruasum, form a short chain, continuous with 

 the left and anterior portion of the rumen. The abomasum alone should be considered as a 

 true stomach, analogous to that of the Dog, or the right sac of the ventriculus of Solipeds. 

 The other three compartments only represent, like the left sac in the latter animals, oesopha- 

 geal dilatations. 



The description about to be given of each of these divisions more particularly applies te 

 the Ox; care will be taken, in the proper place, to note the special peculiarities in the stomach 

 of the Sheep, Goat, and Camel. 



Rumen (Figs. 2G8, 271).— This reservoir, vulgarly designated the paunch, alone occupies 

 three-fourths of the abdominal cavity, in which it affects a direction inclined from above to 

 below, and from left to right. 



External conformation. — Elongated from before to behind, and depressed from above to 



Fig. 268. 



OTOMACH OF THE OX, SEEN ON ITS RIGHT UPPER FACE, THE ABOMASUM BEING DEPRESSED. 



A, Rumen, left hemisphere; B, rumen, right hemisphere; C, termination of the oesophagus; 

 D, reticulum ; E, omasum : F, abomasum. 



below, it offers for study : 1. An inferior and a superior face, nearly plane, smooth, and divided 

 into two lateral regions by traces of fissures, which are only sensible at the extremities of the 

 organ. 2. A left and right border, smooth, thick, and rounded. 3. A posterior extremity, 

 divided by a deep notch into two lobes, described by Cliabert by the name of conical cysts. 4. 

 An anterior extremity, offering an analogous arrangement, and concealed, at first sight, by the 

 stomachs (or compartments) superadded to the rumen ; the notch on the right of this extremity 

 divides it into two unequal pouches, which will be referred to presently. 



It is to be remarked that tliese two notches, which are prolonged on tl)e surface by furrows 

 that separate these into two lateral regions, divide the rumen into ttoo sacs— a rigid and left; 

 this division we shall find more manifest in the interior of the viscus. The right sac— the 

 shortest — is in great part enveloped by the serous covering which constitutes the great omentum. 

 The left sac surpasses the other by its two extremities, except in the Sheep and Goat (Fig. 

 271), in which the right conical cyst is longer than the left. The anterior extremity of this 

 left sac is tlirown back on the corresponding lobe of the right sac ; above, it receives the 

 insertion of the oesophagu.s, and is continuous, in front, with the reticulum. 



