88 COMPARATIVE ZOOLOGY. 
called the water-bag. Here the food is made into little 
balls, and returned to the mouth to undergo a thorough 
mastication. When finally swallowed, it is directed, by 
a groove from the cesophagus, to the third, and smallest, 
cavity, the manyplies (psaltertwm), named from its nu- 
merous folds, which form a strainer to keep back any 
undivided food; and thence it passes into the true stom- 
ach (abomasus), from which, in the calf, the rennet is 
procured for curdling milk in the manufacture of cheese. 
This fourth cavity is like the 
human stomach in form and 
function, and is the only part 
which secretes gastric juice. 
The rumen and reticulum are 
rather dilatations of the cesoph- 
agus than parts of the stomach 
itself; while the latter is di- 
vided by constriction into two 
chambers, the psalterium and 
abomasus, as in many other 
animals. 
In structure, the stomach re- 
sembles the cesophagus. The 
smooth outside coat (perito- 
Fig. 55.— Vertical Section of the 
Coats of the Stomach: 1, surface neumy is a reflection of the 
of mucous membrane, and mouths i & 
of gastric follicles; 2, gastric tubu- membrane, which lines the 
li, or follicles; 3, deuse connective : 
tissue; 4, submucous tissue; 5, whole abdomen. The middle, 
transverse muscular fibre; 6, lon- P mnlar. ec te o f 
gitudinal muscular fibre; 7, fibrous, or muscular, coa consists 0 
serene COS, three layers of fibres, running 
lengthwise around and obliquely. The successive con- 
traction, oh Wekate of these fibres produce the worm- 
like motion of the stomach, called peristaltic. The inner- 
most, or mucous, membrane, is soft, velvety, of a reddish- 
gray color in Man, and filled with multitudes of glands, 
which secrete the gastric juice. The human stomach, 
