The arrow (k) indicates the place and direction of the communication between the same gullet and the second stomach.

The third arrow (1), passing under the œsophagean canal, shows the place of direct communication between the rumen and the reticulum.

(m) The supposed direction of the œsophagean canal to the third stomach, over the roof of the rumen and the second stomach.

(n) The passage through the third stomach, and entrance into the fourth.

Although the œsophagean canal leads directly into the rumen and reticulum, and thence through the third and fourth stomachs, it has been ascertained that the liquids drank by the animal, chiefly pass direct into the second stomach, the entrance into the first, by a contraction of the muscular pillars, being closed. In the case of the sucking calf, the milk passes directly on to the fourth, or true digesting stomach; and the other stomachs, but particularly the rumen, appear in a measure to be useless, Hence the small size of the rumen compared with the abomasum in the calf that is fed entirely upon milk.

cess.

Now let us see what happens during the digestive pro

The food, after having undergone slight mastica

tions in the mouth, is swallowed and received into the capacious reservoir called the rumen, and marked (c), which is situated directly under the base of the gullet, as represented in the plate. Here it remains for some time, and by the muscular action of the stomach, and the impulsive direction of the papillæ, it is made to traverse its follicular compartments, whilst the moisture with which the food is surrounded contributes to soften it, and to prepare it for a second mastication. When the process of maceration is completed, the food is returned for rumination, by transferring small portions of it at a time from the rumen into the reticulum or second stomach (d), in which there is always sufficient water and mucus for moistening the food that is introduced into it. By the contractile action of this stomach, the portion of macerated food just received from the rumen, is rolled up into a ball or pellet of suitable form to be thrown up the oesophagean canal into the mouth, where it is subjected to a second mastication, which is leisurely performed during the repose of the animal; a process which is well known by the name of chewing the cud, or rumination, and which is continued until the appetite of the animal is appeased.

When the mass, after being thoroughly ground down by the teeth, is again swallowed, it passes along the œsophagean canal, which changes its form at the entrance of the reticulum, through which the food glides into the omasum, or third stomach (e); and the orifice of this stomach being brought forward by means of the muscular bands, which form the ridges of the walls of the canal, when they contract every portion of food is effectually prevented from dropping into either of the preceding cavities. Sir Everard Home describes this third stomach as being of the form of a crescent, and containing twenty-four septa or folds in its inner membrane. These folds are placed paral

lel to each other like the leaves of a book, excepting they are of unequal breadths, and that a narrower fold is placed between each of the broader ones. Whatever food is in

troduced into this cavity, must pass between these folds and describe three-fourths of a circle before it can arrive at the orifice leading to the abomasum, or fourth stomach (ƒ), which is so near the third, that the distance between them does not exceed three inches. And as a farther demonstration of the design and adaptation of this organ for the perfect comminution of herbaceous substances, as Youatt remarks, the articular covering of these leaves is peculiarly dense and strong, and thickly studded with little prominences; so that when the leaf is examined, it exhibits a filelike hardness, that would be scarcely thought possible; and it is evidently capable of acting like a file, or a little grindstone. These prominences are harder and larger towards the lower part of the leaf; and in the central leaves assume the form and office of little crotchets, or hooks, some of which have the hardness of horn, so that nothing fibrous or solid can escape them, until it is reduced to a pulpy mass. Clearer evidences of design for the performance of specific functions, than is exhibited in the construction of the omasum, cannot be imagined.

It is, then, in the abomasum, or fourth stomach (ƒ), that the proper digestion of the food is performed; and for this purpose it is lined with a soft villous membrane, and is traversed somewhat irregularly, yet longitudinally, with numerous folds. But the principal agent in digestion is the liquid called the gastric juice, which is secreted from the cellular glands with which this organ abounds. The solvent powers of this liquid having broken down the pulpy mass into a semi-homogeneous fluid called chyme, it passes through the lower opening of the pyloric into the duodenum (g) or first intestine, where its separation into the nutritive

GENERAL DEDUCTIONS.

123

and innutritive portions is effected, and the former begins to be taken up, and is carried into the system.*

Such, then, as we have concisely described, and endeavored to illustrate, is the admirable provision of nature for the perfect comminution and digestion of the food of an animal whose flesh and milk are destined to supply so important a part of human sustenance. Can it be that the complicated apparatus of the cow was designed for the digestion of distillery-slop, or food of that description? From the teeth alone we are enabled to decide on the proper kind of aliment. Let then the common sense of the most illiterate man answer, whether slush or liquid diet would require such an array of cutting and grinding teeth, of salivary glands and stomachs for its digestion? Reason answers no; facts, observation, and experience, demonstrate that the proper functions of the animal cannot be subserved, or its health maintained, by such an artificial and unnatural kind of food. It is evidently impossible to pervert the order and manifest designs of nature to such an extent with impunity.

*The different length of the intestines in carnivorous and herbivorous animals is worthy of notice. The shortest, we believe, is that of some birds of prey, in which the intestinal canal is little more than a straight passage from the mouth to the vent. The longest is in the deer kind. The intestine of a Canadian stag, four feet high, measured ninety-six feet. (Mem. Acad. Paris, 1701, p. 170.) The intestine of a sheep unravelled, measures thirty times the length of the body. The intestine of the wild-cat, is only three times the length of the body. Universally, when the substance upon which the animal feeds, is of slow concoction, or yields its chyle with more difficulty, then the passage is circuitous and dilatory, that time and space may be allowed for the change and the absorption which are necessary. When the food is soon dissolved, or already half assimilated, an unnecessary, or, perhaps, hurtful detention is avoided, by giving to it a shorter and a readier route.-Paley.

CHAPTER XIV.

APPROPRIATE FOOD, PURE AIR, AND EXERCISE, NECESSARY TO THE HEALTHY CONDITION OF DAIRY CATTLE.

Temperature of food.-Liquid aliment improper.-Forming milk out of solid food.-Herbaceous matter adapted to the wants of the animal.-Healthy chyle.-Pure air necessary to health.—Injurious effects of foul air.-Exercise important to health.-Illustrated by experiments.-Exercise an instinct.

THAT the natural temperature of food for ruminant animals is the most appropriate, appears too plain a proposition to be disputed; but in the general management of cows in the vicinity of populous places, this important fact is entirely disregarded.

Man, it is true, is omnivorous. His stomach is nearly equally well adapted to the digestion of animal or vegetable food, of solids or fluids. He is also a cooking animal, and can receive his food at varying temperatures. But it is different with ruminant animals. They are essentially herbivorous, and should receive this kind of aliment, at a natural temperature, before it has undergone certain chemical changes, and not, as is the case in the form of slop, reeking hot from the distillery. Their immense complex concocting organs must have something else to employ them besides receiving some thirty or forty gallons of slush per day, which contains but a small quantity of vegetable matter in the form of bran disseminated through it. To fulfil the obvious design of nature, they must have food which requires mastication. Without the power of rumi