472 



DIGESTIVE SYSTEM OF THE SHEEP 



does not project into the isthmus faucium. The mucous membrane of the latter 

 presents two deep and very narrow tonsillar sinuses on either side. , 



The fornix of the pharynx presents a median plicated fold which is a continua- 

 tion of the septum nasi. The pharyngeal orifice of the Eustachian tube has the 

 form of a crescentic slit, placed about on a level with the ventral nasal meatus. 

 There are two large lymph glands and a number of haemolymph glands above the 

 pharynx. 



The oesophagus has a lumen of about an inch (ca. 2.5 cm.) when moderately 

 distended; otherwise it resembles that of the ox. 



The stom.ach is like that of the ox in its general arrangement. Its average 

 capacity is about four gallons (ca. 15 liters). The cardia is opposite the eighth 

 intercostal space; it is just to the left of the median plane, and about two inches 



Dorsal curvature of 

 rumen 



Posterior 

 V groove of 



Fig. 405. — Stomach of Sheep; Left View. 

 From photograph of specimen hardened in situ. The reticulum is somewhat contracted. 



(ca. 5 cm.) below the vertebral column. The dorsal sac of the rumen is a little longer 

 than tlie ventral sac and extends considerably (ca. 7.8 cm.) further forward than 

 the latter. The ventral sac is relatively larger and extends further to the right of 

 the median plane than in the ox; its posterior blind sac extends further (ca. 6-8 cm.) 

 back than that of the dorsal sac. The parietal attachment of the dorsal sac 

 extends back to the second lumbar vertebra. The left longitudinal groove ex- 

 tends upward and backward for a short distance only, and therefore does not 

 connect with the posterior groove. There are two longitudinal grooves on the 

 right side which join at each end, thus enclosing a long, narrow prominent area; 

 the dorsal one contains the right ruminal artery, and the ventral one corresponds to 



