Ruminantia is the term used by naturalists to designate those mammiferous quadrupeds which chew the cud; or, in other words, which swallow their food, in the first instance, with a very slight mastication, and afterwards regurgitate it, in order that it may undergo a second and more complete mastication: this second operation is called ruminating, or chewing the cud. The order of animals which possess this peculiarity, is divided into nine groups or genera, namely:—

The last named forms the subject of the following pages, and is called, in zoological language, the Genus Bos, in popular language, the Ox Tribe.

One of the most interesting occupations which the wide field of Zoology offers to the naturalist, is the investigation of those remarkable adaptations of organs to functions, and of these again to the necessities and well-being of the entire animal. Nor does it in the least diminish our interest in the investigation of individual adaptations, or our admiration on becoming acquainted with them, that we know, À priori, this universal truth, that all the constituents of every organised body, be that organisation what it may, are invariably adapted, in the most perfect manner, to each other, and to the whole.

It is by a knowledge of this exact harmony in the animal economy, that the comparative anatomist can determine, with almost unerring precision, the genus, or even species of an animal, by an examination of any important part of its organisation, as the teeth, stomach, bones, or extremities. In some cases, a single bone, or even the fragment of a bone, is sufficient to convey an idea of the entire animal to which it belonged.

In illustration of this:—if the viscera of an animal are so organised as only to be fitted for the digestion of recent flesh, we find that the jaws are so contracted as to fit them for devouring prey; the claws for seizing and tearing it to pieces; the teeth for cutting and dividing its flesh; the entire system of the limbs, or organs of motion, for pursuing and overtaking it; and the organs of sense for discovering it at a distance. Moreover, the brain of the animal is also endowed with instincts sufficient for concealing itself, and for laying plans to catch its necessary prey.

Again, we are well aware that all hoofed animals must necessarily be herbivorous, or vegetable feeders, because they are possessed of no means of seizing prey. It is also evident, having no other use for their fore-legs than to support their bodies, that they have no occasion for a shoulder so vigorously organised as that of carnivorous animals; owing to which they have no clavicles, and their shoulder-blades are proportionally narrow. Having also no occasion to turn their forearms, their radius is joined by ossification to the ulna, or is at least articulated by gynglymus with the humerus. Their food being entirely herbaceous, requires teeth with flat surfaces, on purpose to bruise the seeds and plants on which they feed. For this purpose, also, these surfaces require to be unequal, and are, consequently, composed of alternate perpendicular layers of enamel and softer bone. Teeth of this structure necessarily require horizontal motions to enable them to triturate, or grind down the herbaceous food; and accordingly the condyles of the jaw could not be formed into such confined joints as in the carnivorous animals, but must have a flattened form, correspondent to sockets in the temporal bones. The depressions, also, of the temporal bones, having smaller muscles to contain, are narrower and not so deep; and so on, throughout the whole organisation.

The digestive system of the ruminantia is more complicated in structure than that of any other class of animals; and, owing to this complexity, and the consequent difficulty of investigating it, its nature and functions have been less perfectly understood.

The stomach of the Manilla Buffalo, which will serve as an example of all the other species, is divided into four cavities or ventricles, which are usually (but improperly) considered as four distinct stomachs.

The following figure represents the form, relative size, and position of these four cavities when detached from the animal, and fully inflated.

The interior of those cavities present some remarkable differences in point of structure, which, in the present work, can only be alluded to in a very general manner. For a particular account of the internal anatomy of these complicated organs, the reader is referred to the interesting work on 'Cattle,' by W. Youatt.

The paunch is lined with a thick membrane, presenting numerous prominent and hard papillÆ. The inner surface of the second cavity is very artificially divided into angular cells, giving it somewhat the appearance of honeycomb, whence its name "honeycomb-bag." The lining membrane of the third cavity forms numerous deep folds, lying upon each other like the leaves of a book, and beset with small hard tubercles. These folds vary in breadth in a regular alternate order, a narrow fold being placed between each of the broader ones. The fourth cavity is lined with a velvety mucous membrane disposed in longitudinal folds. It is this part of the stomach that furnishes the gastric juice, and, consequently, it is in this cavity that the proper digestion of the food takes place; it is here, also, that the milk taken by the calf is coagulated. The reed or fourth cavity of the calf's stomach retains its power of coagulating milk even after it has been taken from the animal. We have a familiar instance of its operation in the formation of curds and whey.

The first and second cavities (a and b) are placed parallel (or on a level) with each other; and the oesophagus (e) opens, almost equally, into them both. On each side of the termination of the oesophagus there is a muscular ridge projecting, so that the two together form a sort of groove or channel, which opens almost equally into the second and third cavities (b and c).

[As there has not been, as far as I am aware, any appropriate name given to this very remarkable part of the stomach of ruminants, I here take the liberty of suggesting the term Gastro-duct, by which epithet this muscular channel will be designated in the following pages.]

All these parts, namely, the oesophagus, the gastro-duct, and the first three cavities, not only communicate with each other, but they communicate by one common point, and that point is the gastro-duct. At the extremity of the third cavity, opposite to that at which the gastro-duct enters it, is an aperture which communicates immediately with the fourth cavity (d).

Such is a very brief description of the complicated stomach of the Ox Tribe. In what manner the food passes through this curious arrangement of cavities is a problem which has engaged the attention of naturalists from a very early period. A host of great men might be cited who have failed to solve it. The French physiologist, M. Flourens, by his recent experiments, has done more than any or all of his predecessors to give clearness and precision to this intricate subject.

The following is an abstract of the most important of his experiments:—

A sheep having been fed on fresh trefoil, was killed and opened immediately,—that is, before the process of rumination had commenced. He (M. Flourens) found the greatest part of this herb (easily recognised by its leaves, which were still almost entire,) in the paunch; but he also found a certain portion (une partie notable) of those leaves (in the same unmasticated state) in the honeycomb. In the other two cavities, (the many-plies and the reed,) there was absolutely none.

M. Flourens repeated this experiment a great many times, with herbs of various kinds, and the result was constantly the same: from which it appears, that herbaceous food, on its first deglutition, enters into the honeycomb, as well as into the paunch; the proportion, however, being considerably greater into the paunch than into the honeycomb. It appears equally certain that, in the first swallowing, this kind of food only enters into the first two cavities, and never passes into the many-plies or the reed.

Having ascertained this fact with respect to herbs, he instituted a similar series of experiments, in which the animals were fed upon various kinds of grain,—rye, barley, wheat, oats, &c. The animals were killed and examined, as in the former experiments, immediately after being fed. He found the greater part of the grain unmasticated (tout entier) in the paunch; but, as in the case of the herbs, he also found a certain portion, in the same unmasticated state, in the honeycomb. Neither the many-plies nor the reed contained a single grain. He repeated these experiments many times, and always with the same result.

He then tried the effect of carrots cut into pieces, from half an inch to an inch in length; and in order that the animals might not chew them, he passed them into the pharynx by means of a tube. In one of these sheep he found all the morsels in the paunch; but, in the other two, some of the morsels were in the honeycomb, and some in the paunch. In all the three cases, there was none either in the many-plies or in the reed.

He then proceeded to ascertain the effect of substances previously comminuted. He caused a certain quantity of carrots to be reduced to a kind of mash, with which he fed two sheep, and opened them immediately afterwards. He found the greatest part of this mash in the paunch and in the honeycomb; but he likewise found a certain portion in the many-plies and in the reed.

His next experiments were made upon plain fluids. It is the opinion of the generality of authors on this subject that fluids pass immediately and entirely, along the gastro-duct, into the third and fourth cavities. But, according to the experiments of M. Flourens, this is not the case. He found, by making artificial openings (anus artificiel) in the stomachs of various sheep, that, as the animals drank, the fluid came directly out at the opening, in whatever cavity it might have been made.

It is clear, then, that fluids pass, in part, into the first and second cavities, and, in part, into the third and fourth; and they pass as directly into the former as into the latter.

The following is the result of some experiments which M. Flourens made respecting the formation of the pellets.

In the first place, after the animal has swallowed a certain quantity of food the first time, successive pellets are formed of this food, which remount singly to the mouth; secondly, there is a particular apparatus, which forms these pellets; and, thirdly, this apparatus consists of the two closed apertures (ouvertures fermÉes) of the many-plies, and of the oesophagus. Thus, the first two cavities, in contracting, push the aliments which they contain between the edges of the gastro-duct; and the gastro-duct, contracting in its turn, draws together the two openings of the many-plies and oesophagus; and these two openings, closed at this moment of their action, seize a portion of the food, detach it, and form it into a pellet.

The chief utility of rumination, as applicable to all the animals in which it takes place, and the final purpose of this wonderfully-complicated function in the animal economy, are still imperfectly known; what has been already suggested on these points is quite unsatisfactory. Perrault and others supposed that it contributed to the security of those animals, which are at once voracious and timid, by showing the necessity of their remaining long employed in chewing in an open pasture; but the Indian buffalo ruminates, although it does not fly even from the lion; and the wild goat dwells in Alpine countries, which are inaccessible to beasts of prey.

Whatever may be our ignorance of the cause or the object of rumination, it is certain that the nature of the food has a considerable influence in increasing or diminishing the necessity for the performance of that function. Thus, dry food requires to be entirely subjected to a second mastication, before it can pass into the many-plies and reed; whilst a great portion of that which is moist and succulent passes readily into those cavities, on its first descent into the stomach.

It has already been shown by the illustration, (p. 4,) that the paunch is the largest of the four cavities; but this is not the case with the stomach of the young calf, which, while it continues to suck, does not ruminate; in this case the reed, which is the true digestive cavity, is actually larger than the other three taken together.

When the calf begins to feed upon solid food, then it begins to ruminate; and as the quantity of solid food is increased, so does the size of the paunch increase, until it attains its full dimensions. In this latter case, the paunch has become considerably larger than the other three cavities taken together.

A curious modification of an organ to adjust itself to the altered condition of the animal is beautifully shown in the instance now under consideration, the nature of which will be easily understood by a reference to the following diagrams, giving the exact relative proportions of the different cavities of the stomach to each other in the young calf and in the full-grown cow.

The letters refer to the same parts in each figure: a, the paunch; b, the honeycomb bag; c, the many-plies; d, the reed.

[These engravings, illustrative of the comparative sizes of the different stomachal cavities, are copied from original drawings taken from preparations of the stomachs which I made expressly for this purpose.]

In all herbivorous animals, and especially those of the ruminating kind, the alimentary canal is of an enormous length; measuring in a full grown ox, as much as sixty yards. The paunch, in such an animal, will hold from fifteen to eighteen gallons.

Blumenbach observes, that the process of rumination supposes a power of voluntary motion in the oesophagus; and, indeed, the influence of the will throughout the whole process is incontestible. It is not confined to any particular time, since the animal can delay it according to circumstances, even when the paunch is quite full. It has been expressly stated of some men, who have had the power of ruminating, that it was quite voluntary with them. Blumenbach knew four men who ruminated their food, and they assured him they had a real enjoyment in doing it: two of them had the power of doing or abstaining from it at their pleasure.

A case of human rumination occurred some years ago at Bristol, the particulars of which are minutely recorded in the 'Philosophical Transactions.' It seemed, in this instance, to have been hereditary, as the father of the individual was subject to the same habit. The young man usually began to chew his food over again, within a quarter of an hour after eating. His ruminating after a full meal generally lasted about an hour and a half; nor could he sleep until this task was completed. The victuals, upon its return, tasted even more pleasantly than at first; and seemed as if it had been beaten up in a mortar. If he ate a variety of things, that which he ate first, came up again first; and if this return was interrupted for any length of time, it produced sickness and disorder; nor was he ever well till it returned. These singular cases are caused, no doubt, by some abnormal structure of the interior of the stomach. No account has yet been given of the dissection of an individual so constituted.

When cattle are at rest, or not employed in grazing or chewing the cud, they are observed frequently to lick themselves. By this means they raise up the hair of their coats, and often swallow it in considerable quantities. The hair thus swallowed gradually accumulates in the stomach, where it is formed into smooth round balls, which, in time, become invested with a hardish brown crust, composed, apparently, of inspissated mucilage, that, by continual friction from the coats of the stomach, becomes hard and glossy. It is generally in the paunch that these hair-balls are found. They vary in weight from a few ounces to six or seven pounds. Mr. Walton, author of an 'Account of the Peruvian Sheep,' makes mention of one that he had in his possession which weighed eight pounds and a quarter. This hair-ball had been taken from a cow that fed on the Pampas of Buenos Ayres. It was of a flat circular shape, and measured two feet eleven inches and a half in circumference; two feet eight inches round the flat part; nine inches diameter also in the flat part; eleven inches diameter in the cross part; and, on immersing it in water, it displaced upwards of eight quarts, which made its bulk correspond to 462 cubic inches. The digestive functions are sometimes seriously impaired by these concretions; a loss of appetite ensues, and general debility.

In the Museum of Daniel Crosthwaite, there is a very extraordinary ball of hair, taken from a fatted calf only seven weeks old. The ball of hair, when taken out of the animal's stomach, and full of moisture, weighed eleven ounces. The calf was fatted by Daniel Thwaite, of Dale Head Hall, within six miles of Keswick; and slaughtered by John Fisher, butcher, Keswick. The calf was a particularly healthy animal.

Before closing this brief sketch of the digestive apparatus of the ox, it may not be uninteresting to quote some of the quaint speculations of Nathaniel Grew on this subject, from his 'Comparative Anatomy of Stomachs and Guts.'

He says: "The voluntary motion of the stomach is that only which accompanies rumination. That it is truly voluntary, is clear, from the command that ruminating animals have of that action. For this purpose it is, that the muscules of their venters are so thick and strong; and have several duplicatures, as the bases of those muscules, whereupon the stress of their motion lies. By means whereof they are able with ease to rowl and tumble any part of the meat from one cell of the same venter to another; or from one venter to another; or from thence into the gullet, whensoever they are minded to do it; so that the ejectment of the meat, in rumination, is a voluntary eructation.

"The pointed knots, like little papillÆ, in the stomachs of ruminating beasts, are also of great use, namely, for the tasting of the meat. The inner membrane of the first three venters is fibrous (like the gustatory papillÆ of the tongue) and not glandulous; the fourth only being glandulous, as in a man. Of the fibres of this membrane, and the nervous, are composed those pointed knots, which are, both in substance and shape, altogether like to those upon the tongue. Whence I doubt not, but that the said three ventricles, as they have a power of voluntary motion, so, likewise, that they are the seat of taste, and as truly the organs of that sense, as is the tongue itself."

The mouth of animals of the Ox Tribe contains, when full, thirty-two teeth. Six molars in each jaw, above, below, and on either side; and eight incisors in the lower jaw. In the upper jaw there are no incisors; but instead thereof a fibrous and elastic pad, or cushion, which covers the convex extremity of the anterior maxillary bone, and which is well worthy of observation.

The final cause of this pad (which stands in the place of upper incisor teeth) and the part it plays in the procuring of food, is thus described by Youatt. "The grass is collected and rolled together by means of the long and moveable tongue; it is firmly held between the lower cutting teeth and the pad, the cartilaginous upper lip assisting in this; and then by a sudden nodding motion of the head, the little roll of herbage is either torn or cut off, or partly both torn and cut.

"The intention of this singular method of gathering the food, it is somewhat difficult satisfactorily to explain. It is peculiar to ruminants, who have one large stomach, in which the food is kept as a kind of reservoir until it is ready for the action of the other stomachs. While it is kept there it is in a state of maceration; it is exposed to the united influence of moisture and warmth, and the consequence of this is, that a species of decomposition sometimes commences, and a vast deal of gas is extricated.

"That this should not take place in the natural process of retention and maceration, nature possibly established this mechanism for the first gathering of the food. It is impossible that half of that which is thus procured can be fairly cut through; part will be torn, and no little portion will be torn up by the roots. If cattle are observed while they are grazing, it will be seen that many a root mingles with the blades of grass; and these roots have sometimes no inconsiderable quantity of earth about them. The beast, however, seems not to regard this; he eats on, dirt and all, until his paunch is filled.

"It was designed that this earth should be gathered and swallowed; it was the meaning of this mechanism. A portion of absorbent earth is found in every soil, sufficient not only to prevent the evil that would result from occasional decomposition, by neutralizing the acid principle as rapidly as it is evolved; but, perhaps, by its presence, preventing that decomposition from taking place. Hence the eagerness with which stall-fed cattle, who have not the opportunity of plucking up the roots of grass, evince for mould. It is seldom that a cow will pass a newly-raised mole hill without nuzzling into it, and devouring a considerable portion of it. This is particularly the case where there is any degree of indigestion."

The general disposition of animals of this class, when unmolested, is inoffensive and retiring; but when excited and irritated, they are fierce and courageous, and extremely dangerous to encounter. It is a remarkable circumstance in their history, that they are generally provoked to attack at the sight of red, or any very bright and glaring colour.