(20.) _Structure of the Stomach._--The term ruminating, indicates the power possessed by this animal, in common with many others, of masticating its food a second time, by returning it to the mouth after a short maceration. This they are enabled to do, from the structure of the stomachs, or, more correctly speaking, stomach; as anatomists have now concluded, from all animals being constructed on one common principle, that ruminating animals are not possessed of four stomachs, as formerly supposed, but only of one, which they view as being divided into four compartments. In drawing precise conclusions, we are bound only to admit the existence of two compartments, the other two belonging properly to the gullet; and being equivalent to the cheek pouches of monkeys, or the crop and membranous stomach of birds, may be viewed as an apparatus designed to serve a nearly similar purpose (that of moistening and macerating the food); while the real stomach will cease to excite wonder, or puzzle the ignorant, on being contrasted with that of other animals, in many of which a division exists, and from which even the human stomach, though generally a single sac, is not always exempt,--Dr Knox, of Edinburgh, being in possession of one that resembles a pair of small globes joined by a narrow tube, and which, when taken from the body of a person who was advanced in life, bore every mark of soundness in texture, and must, therefore, have been congenital. (21.) _Digestion._[3]--The food descends by the gullet after being partially crushed, into what is called the first stomach, or paunch, in Latin, _rumen_, or _ingluvies_, in which cavity are found those morbid concretions so much, and so superstitiously, prized in the Eastern world, under the name of Bezoar stones; from this it passes into the second, termed bonnet, king's hood, or honey-comb, in Latin _reticulum_, which is much smaller than the other, and receives its name from the inner coat being arranged into cells; here it is moistened, made into pellets, and, while the animal is at rest, impelled by the antiperistaltic motion of the tube to the mouth, and after undergoing a complete mastication, is returned through the gullet to the third stomach, or smallest compartment, which goes under the name of _omasum_, or many-plies, from its resembling a rolled up hedgehog, and sometimes from the longitudinal _laminæ_ of its mucous membrane that of leaflet. The food remains but a short time in the omasum, proceeding into the fourth division, or obomasum, which in its structure, especially in that of the mucous, or inner membrane, is nearly allied to the same organ in the human being, and is, by the French, from its power of coagulating milk, called _caillette_. The last compartment is the largest of the four, so long as the animal continues to live on milk; but the paunch speedily surpasses it in magnitude when grass becomes the sole provision. The milk always