192 NORMAL HISTOLOGY AND ORGANOGRAPHY. 



and bound down to the muscularis by delicate 

 fibrous septa. It is really a part of the peritoneum. 

 The Stomach in Ruminants. Ruminants (ox, 

 sheep, goat, camel, llama) all have four compart- 

 ments for the reception and maceration of food; 



rumen, reticulum, oma- 

 sum, and abomasum. 

 The first three are 

 morphologically dis- 

 tensions and modifica- 

 tions of the lower end 

 of the esophagus, while 

 the abomasum alone 

 corresponds to the 

 stomach in other ani- 

 mals and needs, there- 

 fore, no further de- 

 scription here. 



The Rumen is by far 

 the largest compart- 

 ment, reaching the 

 serous coat. enormous capacity of 

 forty gallons in the ox. 

 It is divided into four 

 sac-like pouches by 



two muscular band-like girdles whose obvious func- 

 tion is to contract on the contents and render 

 assistance in the mechanical process of returning 

 food for further mastication. Its mucous mem- 

 brane is covered with pointed papillae 3 to 9 mm. in 

 length, excepting where the muscular pillars are 

 most prominent. Its epithelial lining is stratified, 

 consisting of eight to twelve layers of cells, the 



Fig. 1410. Cross section through 

 rumen of ox. 



