394 



TEE DIGESTIVE APPABATXTS 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 whii-h the oesophagus is inserted, constitutes nine-tenths 

 of the total mass. The other three, the reticulum, omasum, and 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, oesophageal dilatations. 



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

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

 stomach of the Sheep and Goal. 



Rdmen (Fig. 192). — This reservoir, vulgarly designated tlie 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. 



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 con/ormaKore.— Elongated from before to behind, and depressed from above 

 to below It offers for study : 1, An inferior and a mperior 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; 

 d, A posterior extremity, divided by a deep notch into two lobes, described by Chabert 

 by the name ot ennical 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 deferred to presently. 



It is to be remarked that these t\/o notches, which are prolonged on the surface bv 

 W^TrW "i 'T'''' V *?'" ™'°-j7? lateral regions, divide the rumen into two sacs,B. 

 » ight and left; this division we will find more manifest in the interior of the viscus. The 

 right sa^, the shortest, is m great part enveloped by the serous covering which 

 e^cent n 'tf %'?f'^' Omentum The ie/( sat surpasses the other by its two extremities, 

 except in the Sheep and Goat m which the right conical cyst is longer than the 

 I tt. 1 he anterior extremity of this left sac is thrown backwards on the corresponding 



