DIGESTIVE APPARATUS. 143 



them the diagnosis diverticulum and stenosis, two conditions 

 usually coexisting. On the other hand, the fact that a pro- 

 tang can be passed freely through the esophagus does not 

 exclude the presence of these conditions. 



IV. Rumination. 



Rumination is a specific physiological act of the digestive 

 apparatus of ruminants. These animals feed by taking up food 

 hurriedly and swallowing it after little or no mastication. After 

 ingestmg a sufficient amount of food in this manner, the latter, 

 which by this time has become partly macerated by the saliva 

 which accumulated with it in the rumen, is carefully rcmasticated. 

 During this act the animals prefer a recumbent position. The 

 food is forced into the mouth by a contraction of the secona 

 stomach or reticulum into which it previously passes from the 

 rumen. Every cud is subjected to about 60 masticatory move- 

 ments and is then re-szcallozi'cd, this time passing directly into 

 the omasum and abomasum or true stomach through the esoph- 

 ageal groove. The whole act of rumination requires from one 

 to two hours. When cattle are driven or oxen put to work before 

 they had time to finish ruminating, this act is temporarily sus- 

 pended to be resumed at the next period of rest. 



Slight disturbances of the act of rumination can as a 

 rule not be recognized as such. 



Considerabledeviations from the nor- 

 mal or complete suppression of rumination alone are definite 

 signs of disease. 



Jn the beginning disturbances in rumination due to dis- 

 ease manifest themselves by a • reduction in the number of 

 cuds chewed in a certain time, by the number of masticatory 

 movements applied to each cud before b^ing swallowed and 

 by ihe rapidity with which the animal masticates. 



The severity of the disease corresponds to the degree to 

 which rumination is interrupted. In severe diseases rumina- 

 tion ceases entirely. 



Rumination is disturbed in: 



a. [All severe febrile and painful affections, surgical 

 diseases.] 



b. Gastric and intestinal disturbances, especially over- 

 loading and paralysis of the paunch. 



