Some few persons only are double-crowned. The bones of the head are flat, thin, devoid of marrow, and united with sutures indented like a comb. When broken asunder they cannot be united, but the extraction of a small portion is not necessarily fatal, as a fleshy cicatrix forms, and so makes good the loss. We have already mentioned, in their respective[187] places, that the skull of the bear is the weakest of all, and that of the parrot the hardest.
CHAP. 49.—THE BRAIN.
The brain exists in all animals which have blood, and in those sea animals as well, which we have already mentioned as mollusks, although they are destitute of blood, the polypus, for instance. Man, however, has, in proportion to his body, the most voluminous brain of all. This, too, is the most humid, and the coldest of all the viscera, and is enveloped above and below with two membranous integuments, for either of which to be broken is fatal. In addition to these facts, we may remark that the brain is larger in men than in women. In man the brain is destitute of blood and veins, and in other animals it has no fat. Those who are well informed on the subject, tell us that the brain is quite a different substance from the marrow, seeing that on being boiled it only becomes harder. In the very middle of the brain of every animal there are small bones found. Man is the only animal in which it is known to palpitate[188] during infancy; and it does not gain its proper consistency until after the child has made its first attempt to speak. The brain is the most elevated of all the viscera, and the nearest to the roof of the head; it is equally devoid of flesh, blood, and excretions. The senses hold this organ as their citadel; it is in this that are centred all the veins which spring from the heart; it is here that they terminate; this is the very culminating point of all, the regulator of the understanding. With all animals it is advanced to the fore-part of the head, from the fact that the senses have a tendency to the direction in which we look. From the brain proceeds sleep, and its return it is that causes the head to nod. Those creatures, in fact, which have no brain, never sleep. It is said that stags[189] have in the head certain small maggots, twenty in number: they are situate in the empty space that lies beneath the tongue, and around the joints by which the head is united to the body.
CHAP. 50.—THE EARS. ANIMALS WHICH HEAR WITHOUT EARS OR APERTURES.
Man is the only animal the ears of which are immoveable. It is from the natural flaccidity of the ear, that the surname of Flaccus is derived. There is no part of the body that creates a more enormous expense for our women, in the pearls which are suspended from them. In the East, too, it is thought highly becoming for the men, even, to wear gold rings in their ears. Some animals have large, and others small ears. The stag alone has them cut and divided, as it were; in the field-mouse they have a velvet surface. All the animals that are viviparous have ears of some kind or other, with the sole exception of the sea-calf, the dolphin, the fishes which we have mentioned[190] as cartilaginous, and the viper. These animals have only cavities instead of ears, with the exception of the cartilaginous fishes and the dolphin, which last, however, it is quite clear possesses the sense of hearing, for it is charmed by singing, and is often taken while enraptured with the melody: how it is that it does hear, is quite marvellous. These animals, too, have not the slightest trace of olfactory organs, and yet they have a most acute sense of smell.
Among the winged animals, only the horned owl and the long-eared owl have feathers which project like ears, the rest having only cavities for the purpose of hearing; the same is the case, also, with the scaly animals and the serpents. Among horses and beasts of burden of all kinds, it is the ears which indicate the natural feelings; when the animal is weary, they are drooping and flaccid; when it is startled, they quiver to and fro; when it is enraged, they are pricked up; and when it is ailing, they are pendant.
CHAP. 51.—THE FACE, THE FOREHEAD, AND THE EYE-BROWS.
Man is the only creature that has a face, the other animals having only a muzzle or a beak. Other animals have a forehead as well, but it is only on the forehead of man that is depicted sorrow, gladness, compassion, or severity. It is the forehead that is the index of the mind. Man has eyebrows, also, which move together or alternately; these, too, serve in some measure as indications of the feelings. Do we deny or do we assent, it is the eyebrows, mostly, that indicate our intentions. Feelings of pride may be generated elsewhere, but it is here that they have their principal abode; it is in the heart that they take their rise, but it is to the eyebrows that they mount, and here they take up their position. In no part of the body could they meet with a spot more lofty and more precipitous, in which to establish themselves free from all control.
CHAP. 52.—THE EYES—ANIMALS WHICH HAVE NO EYES, OR HAVE ONLY ONE EYE.
Below the forehead are the eyes, which form the most precious portion of the human body, and which, by the enjoyment of the blessings of sight, distinguish life from death. Eyes, however, have not been granted to all animals; oysters have none, but, with reference to some of the shell-fish, the question is still doubtful; for if we move the fingers before a scallop half open, it will immediately close its shell, apparently from seeing them, while the solen[191] will start away from an iron instrument when placed near it. Among quadrupeds the mole[192] has no sight, though it has something that bears a resemblance to eyes, if we remove the membrane that is extended in front of them. Among birds also, it is said that a species of heron, which is known as the “leucus,”[193] is wanting of one eye: a bird of most excellent augury, when it flies towards the south or north, for it is said that it portends thereby that there is about to be an end of perils and alarms. Nigidius says also, that neither locusts nor grasshoppers have eyes. In snails,[194] the two small horns with which they feel their way, perform the duties of eyes. Neither the mawworm[195] nor any other kind of worm has eyes.