238 THE VETERINARY DOCTOR. 
different sizes, and their surfaces are copiously supplied with papilie; 
its contents are dry. The fourth stomach, called the abomasum, or rennet, 
performs substantially the same functions as that of man, 1s larger than the 
second and third but smaller than the first, is covered with a thick, velvety 
coat that has ridges similar to those of the omasum, and secretes an acid 
that is necessary to digestion. 
The first three stomachs are involved in the process of rumination. 
Crushed food passes first into the rumen, or paunch, and is there heated in 
saliva, mucus and other secretions, its toughness determining the time it is 
to be so retained. The food next enters the reticulum, where the softening 
and dissolving are continued, 
being aided by a slow churning 
movement. Sluids that are 
swallowed pass directly into 
this organ without going to 
SECTION OF THE STOMACH OF THE OX. 
STOMACH OF THE Ox, exposing A, Left Sac of the Rumen. _B, Front extremity of the same 
parts of the interior. turned back on the Right Sac, its rear extremity being C. 
G, Section of the front Pillar of the Rumen. og, Its two upper 
a, CEsophagus. 6, Rumen. c, Re- branches. H, Rear Pillar of the same. hhh, Its three lower 
ticulum. d@, Omasum. e, Abomasum. branches. I, Cells of the Reticulum. J, Furrow of the 
f, Duodenum. Esophagus. K, Esophagus, L, Abomasum. 
the paunch, In this stomach secretions ferment the food or produce other 
chemical changes, reducing the contents to a pulpy mass. In the next 
place the food passes back to the teeth and is thoroughly masticated, this 
process being known as rumination, or “chewing the cud.” The return 
of the food is easily detected, for one may see large masses pass up the 
gullet which is distended as in swallowing, though the movement is in the 
opposite direction. When the food passes into the mouth its liquid parts 
are immediately swallowed into the first three stomachs; and the solid food 
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