248 BOVINE PATHOLOGY. 



The oesophagus terminates in gaining relations with the 

 first three compartments of the stomach by the oesophageal 

 groove. This is a half canal open below, the margins of 

 which are mainly composed of longitudinal white muscular 

 fibres, which form a loop at its termination around the 

 opening into the omasum. These fibres are connected 

 together by others, which run transversely beneath the 

 mucous membrane, which resembles that of the oesophagus. 

 The opening of the groove below is into the reticulum 



Fig. 45. — Rumen and reticulum seen from left. Their left walls removed. 

 i. Opening into omasum. (Simouds.) 



anteriorly and the rumen posteriorly. The rumen or first 

 stomach occupies three fourths of the abdomen, being 

 situated on the left side, all of which it occupies except 

 the extreme posterior part. It has a capacity of many 

 gallons. The spleen lies upon its supero-anterior part. 

 It is mostly covered by peritoneum, its muscular coat 

 presents fibres often transversely striated, and is arranged 

 to form bands in certain situations ; some of these 

 are arranged transversely, others longitudinally, con- 

 sequently the cavity of the rumen is divided into four 

 compartments, of which the left are the largest. The 



