CHAPTER VII. 



Rumination. 



The rumen is the first receptacle in which the food is 

 deposited after it has been sufficiently masticated and covered 

 with saliva to permit the act of deglutition; being received in 

 the stomach mouthful by mouthful, until the viscus is compara- 

 tively full, the animal feels repletion, at which time rumination 

 generally commences, the sheep usually assuming a recumbent 

 position. 



The food to be re-chewed is not that which was last swal- 

 lowed, but that which has been in the rumen for twelve to six- 

 teen hours previously. 



The food in the rumen is constantly being changed to a 

 different location by the action of the muscular walls of that 

 organ, being mixed with the juices secreted by the mucous 

 glands of the internal surface. Entering the superior portion it 

 passes to the inferior, again passing to the superior before rimiin- 

 ation commences. For the act of rumination to be performed it is 

 necessary that the rumen be at least three-quarters full to enable 

 the food to occupy the upper part of the organ to enter the oeso- 

 phageal groove. The liquid portion then passes on to the reti- 

 culum, which is only a kind of offshoot or diverticulum, acting 

 as a reservoir to dilute the solid substances which may pass 

 into it. 



All the food which is taken into the rumen does not go 

 through the process of rumination, but only the hard, indigest- 

 ible substances. These are supposed to be separated at the junc- 

 ture of the oesophagus with the rumen and reticulum, the hard 



