THE STOMACH. 



465 



Eelations.— The external form of the rumen being determinerl, the study of its relations 

 becomes easy. By its superior surface, it is in contact with the intestinal mass ; its opposite 

 face rests on the inferior abdominal wall. Its left border, supporting the spleen, touches the 

 most elevated part of the flank and the sublumbar region, to which it adheres by cellular 

 tissue, as well as the vicinity of the coeliac trunk and the great mesenteric artery ; tlie right 

 border, margined by the abomasum, responds to the most declivitous portion of the right hypo- 

 chondriac and flank, as well as to the intestinal circumvolutions. Tlie anterior extremity, 

 bounded by the reticulum and omasum, advances close to the diaphragm; the posterior occupies 

 the entrance to the pelvic cavity, where it is more or less in contact with the genito-urinary 

 organs lodged there. In the pregnant female, the uterus is prblongeil forwards on the upper 

 face of the viscus just described. 



Interior (Fig. 269). — In the interior of the rumen are found incomplete septa, which repeat 

 the division into two sacs already so marked externally These septa are two in number, and 

 represent large muscular pillars, which correspond inferiorly to the notches described at the 

 extremities of the organ. The anterior pillar (Fig. 269, g) sends to the inferior wall of 



Fig. 269. 



IKTERIOR OF THE STOMACH IN RUMINANTS, SHOWING THE UPPER PLANE OF THE RUMEN AND 

 RETICULUM, WITH THE (ESOPHAGEAL FURROW. 



A, Left sac of the rumen; B, anterior extremity of that sac turned back on the riaiht sac; C, its 

 posterior extremity, or left conical pouch ; G, section of the anterior pillar of the rumen ; g, g, its 

 two superior branches; H, posterior pillar of the same; h, h, h, its three inferior branches; I, 

 cells of the reticulum; J, oesophageal furrow; K, oesophagus; L, abomasum. 



the rumen a strong prolongation, directed backwards, and to the left ; it is continued on the 

 superior wall by two branches, which separate at an acute angle. The posterior pillar (Fig. 

 269, h), more voluminous than the preceding, has three branches at each of its extremities— a 

 middle and two lateral. The middle branches are carried forwards on the limit of the two 

 sacs, which they separate from one another ; that from above meets the corresponding branch 

 from the anterior pillar. The lateral branches diverge to the right and left in describing a 

 curve, and in circumscribing the entrance to the conical cysts, which they transform into two 

 compartments distinct from the middle portion of the sac of the rumen; the inferior go to 

 meet the superior br-inches, but do not altogether join them. 



The internal surf;\ce of the rumen is covered by a multitude of papillary prolongations, 

 dependencies of the mucous membrane. To the right, and in the culs-de-sac, these papillae 

 are remarkable for their number, their enormous development, and their general foliated shape. 

 On the left side they are more rare, particularly on the superior wall, and only form very 



