92 DISEASES OF THE DIGESTIVE APPARATUS. 



upon the course of digestion ; normally, it performs two contrac- 

 tions per minute ; its peristaltic movements are perceptible in the 

 left flank ; their diminution or suppuration provokes troubles of 

 digestion. 



3. Rumination is an absolute necessity for the performance of 

 digestion. The average duration for each meal is one hour ; each 

 bolus requires about fifty seconds in order to undergo the second 

 mastication, during which the jaws execute about sixty movements. 

 In febrile affections, or when the animals make excessive efforts, and 

 also in a number of morbid conditions, rumination is suppressed ; 

 this suppression occasions digestive disorders. 



4. The paunch may be compared to a fermentation vat, in which 

 there is constant formation of alcohol, acetic acid, butyric acid ; 

 cellulose and albumin ferment equally up to a certain point. Ab- 

 normal fermentations produce meteorism. The normal reaction of 

 the contents of the paunch is alkaline ; in dyspepsias it becomes 

 acid. 



5. The third stomach forms for the alimentary matters an appa- 

 ratus of mechanical division furnished with appropriate innervation. 

 Indigestion of the third stomach and consequent catarrh of the 

 mucous membrane which lines it, take place under the influence of 

 diverse circumstances : when there is paresis of this organ, or of 

 the paunch ; in every instance that rumination is suppressed and 

 insalivation is performed in an incomplete manner ; finally, when, 

 drinking-water is ingested in insuflicient quantities. 



6. The abomasum constitutes the so-called true stomach. All 

 the diseases of the first three gastric compartments influence it. Its 

 mucous membrane is irritated, and becomes inflamed through the 

 contact of insufficiently prepared alimentary matters. 



7. The reticulum is the principal motor of merycic rejection ; 

 paresis of its muscular wall prevents the process of rumination. 



8. In ruminants, the food remains in the digestive canal for 

 three or four days ; after this lapse of time the largest quantity of 

 digestible alimentary matter is ejected. Part of the food, however, 

 remains in the belly and reticulum for eight days or more. 



General considerations. We are liable to confound acute 

 dyspepsia with acute gastro-intestinal catarrh, just as has happened 

 in the horse. On account of the particular resistance of the mucous 

 membrane of the first three gastric compartments, in the greater 

 number of morbid conditions in which oue of them is involved, 



