474 



DIGESTIVE SYSTEM OF THE SHEEP 



and have serrated edges. The dorsal part of this sac has, in the vicinity of the 

 rumino-reticular orifice, a papillated mucous membrane just like that of the 

 rumen. The omasum is much smaller than the reticulum, its capacity being 

 only about one pint. It is oval and compressed laterally. It is situated almost 

 entirely to the right of the median plane, opposite to the ninth and tenth ribs, 



Fig. 407. — Cross-section of Sheep, through Ninth Thoracic Vertebra; Anterior View. 

 1, Cardia; 2, cesophageal groove; S, rumino-reticular orifice; Ji-, rumino-reticular fold; 5, dorsal sac of rumen; 

 6, body of ninth thoracic vertebra; 7, vena hemiazygos; <?, aorta; P, posterior mediastinal lymph gland; iO, iO, crura 

 of diaphragm; ii, posterior vena cava; i^, portal vein; -B.(., right lung; L.i., left lung; 5, spleen; i, liver; iS, reticu- 

 lum (posterior wall) . Arrow points to reticulo-omasal orifice. The spleen is cut so obhquely as to appear much thicker 

 than it really is. 



higher than in the ox, and has no contact with the abdominal wall. It is related 

 on the right to the liver and gall-bladder, on the left to the rumen, and ventrally 

 to the abomasum. The laminae are less numerous than in the ox; in the neck 

 which connects the omasum with the reticulum they have the form of low, thick 

 ridges, and bear long, pointed, horny papillae. The abomasum is relatively 



