394 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-five 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, :md abomasum, 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 ventriculum of Solipeds. The other three compartments only represent, like the 

 left sac in the latter animals, cesophageal dilatations. 



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

 to the Ox ,- care wilt be taken, in the proper place, to note the special peculiarities in the 

 stomach of the Sheep and Goat. 



RUMEN (Fig. 192). This reservoir, vulgarly designated the paunch, alone occupies 

 three-fourths of the abdominal ca\ity, in which it affects a direction inclined from above 

 to below, and from left to right. 



Fig. 19 



STOMACH 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. 



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

 to 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 Chabert 

 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 these two notches, which are prolonged on the surface by 

 furrows that separate these into two lateral regions, divide the rumen into two sacs, a 

 rinht and left ; this division we will 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, in which the right conical cyst is longer than the 

 1 ft. The anterior extremity of this left sac is thrown backwards on the corresponding 



