The tongue is not similarly formed in all animals. Serpents have a very thin tongue, and three-forked,[251] which they vibrate to and fro: it is of a black colour, and when drawn from out of the mouth, of extraordinary length. The tongue of the lizard is two-forked, and covered with hair.[252] That of the sea-calf also is twofold,[253] but with the serpents it is of the thinness of a hair; the other animals employ it to lick the parts around the mouth. Fishes have nearly the whole of the tongue adhering to the palate, while in the crocodile the whole of it does adhere thereto: but in the aquatic animals the palate, which is fleshy, performs the duty of the tongue as the organ of taste. In lions, pards, and all the animals of that class, and in cats as well, the tongue is covered with asperities,[254] which overlap each other, and bear a strong resemblance to a rasp. Such being its formation, if the animal licks a man’s skin, it will wear it away by making it thinner and thinner; for which reason it is that the saliva of even a perfectly tame animal, being thus introduced to the close vicinity of the blood, is apt to bring on madness. Of the tongue of the purple we have made mention[255] already. With the frog the end of the tongue adheres to the mouth, while the inner part is disjoined from the sides of the gullet; and it is by this means that the males give utterance to their croaking, at the season at which they are known as ololygones.[256] This happens at stated periods of the year, at which the males invite the females for the purposes of propagation: letting down the lower lip to the surface of the water, they receive a small portion of it in the mouth, and then, by quavering with the tongue, make a gurgling noise, from which the croaking is produced which we hear. In making this noise, the folds of the mouth, becoming distended, are quite transparent, and the eyes start from the head and burn again with the effort. Those insects which have a sting in the lower part of the body, have teeth, and a tongue as well; with bees it is of considerable length, and in the grasshopper it is very prominent. Those insects which have a fistulous sting in the mouth, have neither tongue nor teeth; while others, again, have a tongue in the interior of the mouth, the ant, for instance. In the elephant the tongue is remarkably broad; and while with all other animals, each according to its kind, it is always perfectly at liberty, with man, and him alone, it is often found so strongly tied down by certain veins, that it becomes necessary to cut them. We find it stated that the pontiff Metellus had a tongue so ill adapted for articulation, that he is generally supposed to have voluntarily submitted to torture for many months, while preparing to pronounce the speech which he was about to make on the dedication of the temple of Opifera.[257] In most persons the tongue is able to articulate with distinctness at about the seventh year; and many know how to employ it with such remarkable skill, as to be able to imitate the voices of various birds and other animals with the greatest exactness. The other animals have the sense of taste centred in the fore-part of the tongue; but in man it is situate in the palate as well.
CHAP. 66.—THE TONSILS; THE UVA; THE EPIGLOSSIS; THE ARTERY; THE GULLET.
In man there are tonsils at the root of the tongue; these in swine are called the glandules. The uvula,[258] which is suspended between them at the extremity of the palate, is found only in man. Beneath this lies a smaller tongue, known by the name of “epiglossis,”[259] but it is wanting in animals that are oviparous. Placed as it is between two passages, the functions of the epiglottis are of a twofold nature. The one of these passages that lies more inward is called the tracheal artery, and leads to the lungs and the heart: the epiglottis covers it during the action of eating, that the drink or food may not go the wrong way, and so be productive of suffering, as it is by this passage that the breath and the voice are conveyed. The other or exterior passage is called the “gula,”[260] and it is by this passage that the victuals and drink pass: this leads to the belly, while the former one communicates with the chest.[261] The epiglottis covers the pharynx, in its turn, when only the breath or the voice is passing, in order that the victuals may not inopportunely pass upwards, and so disturb the breathing or articulation. The tracheal artery is composed of cartilage and flesh, while the gullet is formed of a sinewy substance united with flesh.
CHAP. 67.—THE NECK; THE THROAT; THE DORSAL SPINE.
The neck is found to exist in no animal but those which have both these passages. All the others which have the gullet only, have nothing but a gorge or throat. In those which have a neck, it is formed of several rounded vertebræ, and is flexible, and joined together by distinct articulations, to allow of the animal turning round the head to look. The lion, the wolf, and the hyæna are the only animals in which it is formed of a single[262] rigid bone. The neck is annexed to the spine, and the spine to the loins. The vertebral column is of a bony substance, but rounded, and pierced within, to afford a passage for the marrow to descend from the brain. It is generally concluded that the marrow is of the same nature as the brain, from the fact that if the membrane of exceeding thinness which covers it is pierced, death immediately ensues.[263] Those animals which have long legs have a long throat as well, which is the case also with aquatic birds, although they have short legs, as well as with those which have hooked talons.
CHAP. 68.—THE THROAT; THE GULLET; THE STOMACH.
Man only, and the swine, are subject to swellings in the throat, which are mostly caused by the noxious quality of the water[264] which they drink. The upper part of the gullet is called the fauces, the lower the stomach.[265] By this name is understood a fleshy concavity, situate behind the tracheal artery, and joining the vertebral column; it extends in length and breadth like a sort of chasm.[266] Those animals which have no gullet have no stomach either, nor yet any neck or throat, fishes, for example; and in all these the mouth communicates immediately with the belly. The sea-tortoise[267] has neither tongue nor teeth; it can break anything, however, with the sharp edge of its muzzle. After the tracheal artery there is the œsophagus, which is indented with hard asperities resembling bramble-thorns, for the purpose of levigating the food, the incisions[268] gradually becoming smaller as they approach the belly. The roughness at the very extremity of this organ strongly resembles that of a blacksmith’s file.
CHAP. 69.—THE HEART; THE BLOOD; THE VITAL SPIRIT.
In all other animals but man the heart is situate in the middle of the breast; in man alone it is placed just below the pap on the left-hand side, the smaller end terminating in a point, and bearing outward. It is among the fish only that this point is turned towards the mouth. It is asserted that the heart is the first among the viscera that is formed in the fœtus, then the brain, and last of all, the eyes: it is said, too, that the eyes are the first organs that die, and the heart the very last of all. The heart also is the principal seat of the heat of the body; it is constantly palpitating, and moves as though it were one animal enclosed within another. It is also enveloped in a membrane equally supple and strong, and is protected by the bulwarks formed by the ribs and the bone of the breast, as being the primary source and origin of life. It contains within itself the primary receptacles for the spirit and the blood, in its sinuous cavity, which in the larger animals is threefold,[269] and in all twofold at least: here it is that the mind[270] has its abode. From this source proceed two large veins, which branch into the fore-part and the back of the body, and which, spreading out in a series of branches, convey the vital blood by other smaller veins over all parts of the body. This is the only one[271] among the viscera that is not affected by maladies, nor is it subject to the ordinary penalties of human life; but when injured, it produces instant death. While all the other viscera are injured, vitality may still remain in the heart.