102 THE FEEDING OF ANIMALS 



be a "catch-all" for the foreign bodies which animals are 

 liable to swallow, such as small stones, pins, and nails. 

 The contents of this compartment of the stomach are very 

 watery, and by being forced into the esophagus and 

 rumen appears to aid the return of the food to the mouth, 

 portion by portion, for remastication. 



141. Rumination. Rumination, which is the re-chew- 

 ing of food previously swallowed, is peculiar to bovines, 

 sheep, and goats. In the case of these species, the masti- 

 cation of coarse fodder is not completed before it is swal- 

 lowed the first time, and they have the power of return- 

 ing to the mouth the material which has become stored 

 in the rumen and reticulum in order that it may be more 

 finely ground. This is what is termed "chewing the cud." 

 It is an operation which greatly aids digestion by render- 

 ing the food mass finer and more susceptible to the action 

 of the digestive fluids. Animals fed on grain alone do not 

 ruminate. They "lose their cud," a condition popularly 

 and erroneously supposed to be fatal to the animal's 

 life. The bolus or "cud" of the bovine weighs approxi- 

 mately four ounces and requires for its mastication not 

 far from one minute, including preparation, transference 

 to the mouth, and return. It is essential to rumination 

 that the supply of liquid to the rumen be abundant, to 

 which the salivary glands contribute a large share. 



142. The omasum. After remastication, the food 

 does not return wholly to the first and second stomachs, 

 but is mostly carried along the esophageal groove to the 

 third stomach, the omasum. The finer portions may even 

 do this when first swallowed. The omasum is a cavity 

 somewhat larger than the reticulum, which has a most 

 curious interior structure. It is filled with extensions of the 

 mucous membrane in the form of leaves, between which 



