THE DIGESTIVE IPPAKATI'K l.\ W.i V V.i/./.i. 



Of, this compartment is larger than tlio rclieulum. l.nt in tin- SI,.,/, and Cmil it is 

 smaller. 



tiitiKitiitn Form llrlationa. Situated nluve the <///-./(-><;/ of the rctiiMilum ami the 

 anterior extremity of tlio right sac of the ruineii, this compartment, when di>tendi d. i 

 oval form, is slightly curved in an opposite direction to the honeycomb division. and 

 depressed from before to behind. It lias, therefore, an mil, rir /, applied agaii 

 diaphragm, to which it is sometimes attached ly conin c-tivi tisane ; a posterior face Ivinu' 

 towards the paunch : a great curvature, turned upwards, and fixed in the posterior li m-.- 

 of the liver oy an omeutal fraenum which is continued on the le-.-< r curvature of the 

 abomoMim and duodenum; a leaser curvature, wliich looks downwards and respond-- to 

 the reticnluiu; a left extremity, exhibiting the neck, which corres|x>nds to the on 1 

 communication between the reticulum and many-plies; a riijht extremity, continuous 

 with the base of the abomasum. from which it is separated by a constriction analogous to 

 that of the anterior extremity, but much less marked. 



Interior. This compartment shows in its interior the two apertures placed at its extre- 

 mities. The right orifice, owning into the abomasum, is much wider than the left, which 



Fig. 193. 



2 



1 



t* 



SECTION OF THE WALL OF THE OMASUM OF THE SHEEP: FROM THE GREAT CURVATI IM 

 SHOWING THE ORIGIN OF THE LEAVES. 



p, Peritoneum ; M, The two muscular layers ; E, Epithelium ; 1, 1, Principal leaves 

 at their origin; 2, Secondary leaf; 3, 3, Leaves of the third order; 4, Denticu- 

 lated lamina; 5, 5, Two planes of muscular fibres ascending into the ]>rinci|>;d 

 leaves, some issuing from the muscular layer of the organ. 



communicates with the reticulum. The cavity which these orifices bring into communica- 

 tion with the adjoining compartments, offers one of the most curious arrangements met with 

 in the viscera; it being filled by unequally-developed leaves of mucous membrane, which 

 follow the length of the cavity. These laminae have an adherent border attached either 

 to the great curvature or to the faces of the organ, ami a free concave border turned 

 towards the lesser curvature. They commence at the side of the orifice of the reticulum 

 by denticulated ridges, between which arc furrows, and which are prolonged from the 

 Irtise of the leaves to the entrance of the abomasum. At the latter aperture they 

 disappear altogether, after rapidly diminishing in height. Their faces arc studded l>y a 

 multitude of very hard mamillary papillae, resembling grains of millet, wliich are more 

 developed and conical on some of the leaves than others. All these lamellar prolongations 

 are far from being of the same extent: twelve to fifteen are so wide that tin ir free border 

 nearly reaches the lesser curvature of the viscus, and between these principal leaves are 

 others which, though regularly enough arranged, are more or lo.-s narrower. At first 

 there is remarked a secondary leaf, half the width of the chief ones, In'tween which it is 

 placed ; then, on each of its sides, another, one-half narrower : and, lastly, at tin- 1< 

 these, two denticulated laminae more or less salient. In a general way, the lamina; which 

 are inserted into the great curvature are the longest and widest ; and those attached to 

 the faces of the viscus become shorter and narrower as they draw nearer the ! -- r 

 curvature. The space comprised lictwccn these prolongations is always filled by very 

 attenuated alimentary matters, which arc usually impregnatt d by a very small quantity 

 of fluid, but arc also often dry, and sometimes even li irdened into compact (lakes. 



