ARTIODACTYLES 103 



the less food required to replace it. The same law applies equally to 

 animals (compare with bat and mole). Applying this principle to the 

 ox, it is easily seen that if this animal were at once to grind up its food, 

 while in the act of feeding, to the necessary fineness, it would be obliged 

 to stand or slowly walk about on the pastures for an even longer time 

 than it actually does. In consequence, however, of the division of the 

 stomach into four compartments and the act of rumination, the animal is 

 able to carry on the greater part of the act of mastication while at rest. 

 It is evident that in this manner much force is saved, and the animal is 

 consequently able to do with less food than it otherwise would. (For the 

 importance of the act of rumination in the case of animals living in a 

 wild state, or those which have reverted to that condition, compare the 

 deer, Section C.) 



The food which has been torn off and only partially masticated passes 

 through the oesophagus into the first great division of the stomach, the 

 paunch or rumen, which 

 forms, in fact, a large 

 receptacle or reservoir ; 

 thence it passes into the 

 second compartment, 

 called, from the fact of its 

 inner mucous surface 

 being raised into a great 

 number of reticular folds, 

 the reticulum, or honey- STOMACH OF A RUMINANT SHEEP (MUCH REDUCED). 

 comb Stomach. After , Lower section of the oesophagus; b, commencement of 

 taking in a sufficient * a11 intestine ; 1, paunch I ; 2 reticulum, above which 



the gutter passing on to (3) the psalterium ; 4, abo- 

 quantlty Of food, the masum. (2, 3 and 4 are laid open.) 



animal lies down, and 



engages in the business of rumination, which proceeds as follows : By 

 a convulsive action of the muscles of the oesophagus, resembling a 

 hiccough, the food, which has been well sodden in the stomach, is forced 

 back from the reticulum into the mouth in the form of small pellets or 

 boluses. It is now, for a second time, carefully masticated, and by the 

 abundant secretion of saliva (from numerous large salivary glands) 

 converted into a pulpy or pap-like mass, and swallowed a second time. 

 This time it is conveyed into the third division of the stomach, the 

 psalterium (called many plies by butchers), so called from the fact that its 

 inner mucous membrane is produced into a number of folds, resembling 

 the upstanding leaves of an open book. The reason why the food this 

 time passes into the third, and not back into the two first divisions of 

 the stomach is that the oesophagus, where it opens into the stomach, is 



