by Aristotle
[5] All sanguineous animals, then, have skin; but not all such animals have hair, save only under the circumstances described above. The hair changes its colour as animals grow old, and in man it turns white. With animals, in general, the change takes place, but not very obviously except in the case of the horse. Hair turns grey from the point backwards to the roots. But, in the majority of cases, grey hairs are [10] white from the beginning; and this is a proof that greyness of hair does not, as some believe to be the case, imply withering; for no part is brought into existence in a withered condition.
In the eruptive malady called the white-sickness all the hairs get grey; and instances have been known where the hair became grey while the patients were ill of the malady, whereas the grey hairs shed off and black ones replaced them on their [15] recovery. [Hair is more apt to turn grey when it is kept covered than when exposed to the action of the outer air.]19 In men, the hair over the temples is the first to turn grey, and the hair in the front grows grey sooner than the hair at the back; and the hair on the pubes is the last to change colour.
Some hairs are congenital, others grow after the maturity of the animal; but [20] this occurs in man only. The congenital hairs are on the head, the eyelids, and the eyebrows; of the later growths the hairs on the pubes are the first to come, then those under the armpits, and, thirdly, those on the chin; for the regions where congenital growths and the subsequent growths are found are equal in number. The [25] hair on the head grows scanty and sheds out to a greater extent and sooner than all the rest. But this remark applies only to hair in front; for no man ever gets bald at the back of his head. Smoothness on the top of the head is termed baldness, but smoothness on the eyebrows is called anaphalanthiasis; and neither of these conditions of baldness supervenes in a man until he has entered upon sexual activity. [30] For no boy ever gets bald, no woman, and no castrated man. In fact, if a man be castrated before reaching puberty, the later growths of hair never come at all; and, if the operation take place subsequently, the after-growths, and these only, shed off, except that on the pubes.
Women do not grow hairs on the chin; except that a scanty beard grows on some women after the monthly periods have stopped; and a similar phenomenon is observed at times in priestesses in Caria, but these cases are looked upon as portentous with regard to coming events. The other after-growths are found in [518b1] women, but more scanty and sparse. Men and women are at times born incapable of the after-growths; and of them, those who are destitute even of the growth upon the pubes are constitutionally impotent.
Hair as a rule grows more or less in length as the wearer grows in age; chiefly [5] the hair on the head, then that in the beard, and fine hair grows longest of all. With some people as they grow old the eyebrows grow thicker, to such an extent that they have to be cut off; and this growth is owing to the fact that the eyebrows are situated at a conjuncture of bones, and these bones, as age comes on, draw apart and exude a gradual increase of moisture. The eyelashes do not grow in size, but they shed when [10] the wearer enters on sexual activity, and shed all the quicker as this activity is the more powerful; and these are the last hairs to grow grey.
Hairs if plucked out before maturity grow again; but they do not grow again if plucked out afterwards. Every hair is supplied with a mucous moisture at its root, and immediately after being plucked out it can lift light articles if it touch them with this mucus.
Animals that admit of diversity of colour in the hair admit of a similar [15] diversity to start with in the skin and in the cuticle of the tongue.
In some cases the upper lip and the chin is thickly covered with hair, and in other cases these parts are smooth and the cheeks are hairy; and smooth-chinned men are less inclined to baldness.
The hair is inclined to grow in certain diseases, especially in consumption, and [20] in old age, and after death; and under these circumstances the hair hardens, and the same phenomenon is observable in respect of the nails.
In the case of men of strong sexual passions the congenital hairs shed the sooner, while the hairs of the aftergrowths are the quicker to come. When men are [25] afflicted with varicose veins they are less inclined to take on baldness; and if they be bald when they become thus afflicted, some get their hair again.
If a hair be cut, it does not grow at the point of section; but it gets longer by growing upward from below. In fishes the scales grow harder and thicker, and when the animal gets emaciated or is growing old the scales grow harder. In quadrupeds [30] as they grow old the hair in some and the wool in others gets deeper but scantier in amount: and the hooves or claws get larger in size; and the same is the case with the beaks of birds. The claws also increase in size, as do also the nails.
12 · With regard to winged animals, such as birds, no creature is liable to [519a1] change of colour by reason of age, excepting the crane. The wings of this bird are ash-coloured at first, but as it grows old the wings get black. Again, owing to special climatic influences, as when unusual frost prevails, a change is sometimes observed to take place in birds whose plumage is of one uniform colour; thus, birds that have dark or black plumage turn white, as the raven, the sparrow, and the swallow; but [5] no case has been known of a change of colour from white to black. [Further, most birds change the colour of their plumage at different seasons of the year, so much so that a man ignorant of their habits might be mistaken as to their identity.]20
[10] Some animals change the colour of their hair with a change in their drinking-water, for the same species of animal is found white in one district and black in another. And in regard to the commerce of the sexes, water in many places is of such peculiar quality that rams, if they have intercourse with the female after drinking it, beget black lambs, as is the case with the water of the Psychrus, a river [15] in the district of Assyritis in the Chalcidic Peninsula, on the coast of Thrace; and in Antandria there are two rivers of which one makes the lambs white and the other black. The river Scamander also has the reputation of making lambs yellow, and that is the reason, they say, why Homer designates it the Yellow River instead of the Scamander.21
[20] Animals as a general rule have no hair on their internal surfaces, and, in regard to their extremities, they have hair on the upper, but not on the lower side.
The hare is the only animal to have hair inside its mouth and underneath its feet. Further, the moustache-whale22 instead of teeth has hairs in its mouth resembling pigs’ bristles.
[25] Hairs after being cut grow at the bottom but not at the top; if feathers be cut off, they grow neither at top nor bottom, but shed and fall out. Further, the bee’s wing will not grow again after being plucked off, nor will the wing of any creature that has undivided wings. Neither will the sting grow again if the bee lose it, but the creature will die of the loss.
[30] 13 · In all sanguineous animals membranes are found. And membrane resembles a thin close-textured skin, but its qualities are different, as it admits neither of cleavage nor of extension. Membrane envelops each one of the bones and each one of the viscera, both in the larger and the smaller animals; though in the [519b1] smaller animals the membranes are indiscernible from their extreme tenuity and minuteness. The largest of all the membranes are the two that surround the brain, and of these two the one that lines the bony skull is stronger and thicker than the one that envelops the brain; next in order of magnitude comes the membrane that [5] encloses the heart. If membrane be bared and cut asunder it will not grow together again, and the bone thus stripped of its membrane mortifies.
14 · The omentum is membrane. All sanguineous animals are furnished with this organ; but in some animals it is supplied with fat, and in others it is devoid of it. The omentum has both its starting-point and its attachment, with ambidental [10] vivipara, in the centre of the stomach, where the stomach has a kind of suture; in non-ambidental vivipara it has its starting-point and attachment in the chief of the stomachs.
15 · The bladder also is of the nature of membrane, but of membrane peculiar in
kind, for it is extensile. The organ is not common to all animals, but, while it is found in all the vivipara, the tortoise is the only oviparous animal that is [15] furnished therewith. The bladder if cut asunder will not grow together again, unless the section be just at the commencement of the urethra: except indeed in very rare cases, for instances of healing have been known to occur. After death, the organ passes no liquid excretion; but in life it passes at times dry excretion also, which turns into stones in the case of sufferers from that malady. Indeed, instances have [20] been known of concretions in the bladder indistinguishable from cockle-shells.
Such are the properties, then, of vein, sinew and skin, of fibre and membrane, of hair, nail, claw and hoof, of horns, of teeth, of beak, of gristle, of bones, and of parts that are analogous to these. [25]
16 · Flesh, and that which is by nature akin to it in sanguineous animals, is in all cases situated in between the skin and the bone, or the substance analogous to bone; for just as spine is a counterpart of bone, so is the flesh-like substance to flesh, in the case of animals that have bones and spine. [30]
Flesh can be divided asunder in any direction, not lengthwise only as is the case with sinew and vein. When animals are subjected to emaciation the flesh disappears, and the creatures become a mass of veins and fibres; when they are over fed, fat takes the place of flesh. Where the flesh is abundant in an animal, its veins are somewhat small and the blood abnormally red; the viscera also and the stomach [520a1] are diminutive; whereas with animals whose veins are large the blood is somewhat black, the viscera and the stomach are large, and the flesh is somewhat scanty. And animals with small stomachs are disposed to take on flesh. [5]
17 · Again, fat and suet differ from one another. Suet is frangible in all directions and congeals if subjected to extreme cold, whereas fat can melt but cannot congeal; and soups made of the flesh of animals supplied with fat do not congeal, as is found with horse-flesh and pork; but soups made from the flesh of animals supplied with suet do coagulate, as is seen with mutton and goat’s flesh. [10] Further, fat and suet differ as to their localities; for fat is found between the skin and flesh, but suet is found only at the limit of the fleshy parts. Also, in animals supplied with fat the omentum is supplied with fat, and it is supplied with suet in animals supplied with suet. Moreover, ambidental animals are supplied with fat, and non-ambidentals with suet. [15]
Of the viscera the liver in some animals becomes fatty, as, among fishes, is the case with the selachia, by the melting of whose livers an oil is manufactured. The selachia themselves have no free fat at all in connexion with the flesh or with the stomach. The suet in fish is fatty, and does not congeal. All animals are furnished [20] with fat, either intermingled with their flesh, or apart. Such as have no free fat are less fat than others in stomach and omentum, as the eel; for it has only a scanty supply of suet about the omentum. Most animals take on fat in the belly, especially [25] such animals as are little in motion.
The brains of animals supplied with fat are oily, as in the pig; of animals supplied with suet, dry. But it is about the kidneys more than any other viscera that animals are inclined to take on fat; and the right kidney is always less supplied with [30] fat, and, be the two kidneys ever so fat, there is always a space devoid of fat in between the two. Animals supplied with suet are specially apt to have it about the kidneys, and especially the sheep; for this animal is apt to die from its kidneys being entirely enveloped. Fat about the kidney is induced by overfeeding, as is found at [520b1] Leontini in Sicily; and consequently in this district they defer driving out sheep to pasture until the day is well on, to reduce the amount they eat.
18 · The part around the pupil of the eye is fatty in all animals, and this part [5] resembles suet in all animals that possess such a part and that are not furnished with hard eyes.
Fat animals, whether male or female, are poor breeders. Animals are disposed to take on fat more when old than when young, and especially when they have attained their full breadth and their full length and are beginning to grow depth-ways.
[10] 19 · And now to proceed to the consideration of the blood. In sanguineous animals blood is the most universal and the most indispensable part; and it is not an acquired part, but it belongs to all animals that are not moribund. All blood is contained in a vascular system, to wit, the veins, and is found nowhere else, excepting in the heart. Blood is not sensitive to touch in any animal, any more than [15] the excretions of the stomach; and the case is similar with the brain and the marrow. When flesh is lacerated, blood exudes, if the animal be alive and unless the flesh be gangrened. Blood in a healthy condition is naturally sweet to the taste, and red in [20] colour; blood that deteriorates from natural decay or from disease is more or less black. Blood at its best, before it undergoes deterioration from either natural decay or disease, is neither very thick nor very thin. In the living animal it is always liquid and warm, but, on issuing from the body, it coagulates in all cases except in the case [25] of the deer, the roe, and the like animals; for, as a general rule, blood coagulates unless the fibres be extracted. Bull’s blood is the quickest to coagulate.
Animals that are internally and externally viviparous are more abundantly supplied with blood than the sanguineous ovipara. Animals that are in good condition, either from natural causes or from their health having been attended to, [30] have the blood neither too abundant—as it is in creatures that have recently taken a drink—nor again very scanty, as is the case with animals when exceedingly fat. For animals in this condition have pure blood, but very little of it, and the fatter an animal gets the less becomes its supply of blood; for whatsoever is fat is destitute of [521a1] blood.
A fat substance is incorruptible, but blood and all things containing it corrupt rapidly, and this property characterizes especially all parts connected with the bones. Blood is finest and purest in man; and thickest and blackest in the bull and [5] the ass, of all vivipara. In the lower and the higher parts of the body blood is thicker and blacker.
Blood palpitates in the veins of all animals alike all over their bodies, and blood is the only liquid that permeates the entire frames of living animals, without exception and at all times, as long as life lasts. Blood is developed first of all in the heart of animals before the body is differentiated as a whole. If blood be removed or [10] if it escape in any considerable quantity, animals fall into a faint; if it be removed in an exceedingly large quantity they die. If the blood get exceedingly liquid, animals fall sick; for the blood then turns into something like ichor, and gets so thin that it at times has been known to exude through the pores like sweat. In some cases blood, when issuing from the veins, does not coagulate at all, or only here and there. Whilst [15] animals are sleeping the blood is less abundantly supplied near the exterior surfaces, so that, if the sleeping creature be pricked with a pin, the blood does not issue as copiously. Blood is developed out of ichor by concoction, and fat in like manner out of blood. If the blood get diseased, haemorrhoids may ensue in the [20] nostril or at the anus, or the veins may become varicose. Blood, if it corrupt in the body, has a tendency to turn into pus, and pus may turn into a solid concretion.
Blood in the female differs from that in the male, for, supposing the male and female to be on a par as regards age and health, the blood in the female is thicker and blacker than in the male; and with the female there is less on the surface and [25] more internally. Of all female animals the female in man is the most richly supplied with blood, and of all animals the menstruous discharges are the most copious in woman. The blood of these discharges under disease turns into flux. Women are less subject to other diseases. Women are seldom afflicted with varicose veins, with [30] haemorrhoids, or with bleeding at the nose, and, if any of these maladies supervene, the menses are imperfectly discharged.
Blood differs in quantity and appearance according to age; in very young animals it resembles ichor and is abundant, in the old it is thick and black and scarce, and in middle-aged animals its
qualities are intermediate. In old animals the [521b1] blood coagulates rapidly, even blood at the surface of the body; but this is not the case with young animals. Ichor is unconcocted blood: either blood that has not yet been concocted, or that has become fluid again.
20 · We now proceed to marrow; for this is one of the liquids found in certain sanguineous animals. All the natural liquids of the body are contained in vessels: as [5] blood in veins, marrow in bones [and other moistures in membranous structures of the skin or gut].23
In young animals the marrow is exceedingly sanguineous, but, as animals grow old, it becomes fatty in animals supplied with fat, and suet-like in animals with suet. [10] All bones, however, are not supplied with marrow, but only the hollow ones, and not all of these. For of the bones in the lion some contain no marrow at all, and some are only scantily supplied therewith; and that accounts, as was previously observed, for the statement made by certain writers that the lion is marrowless. In the bones of pigs it is found in small quantities; and in the bones of certain animals of this species [15] it is not found at all.
These liquids, then, are nearly always congenital in animals, but milk and sperm come at a later time. Of these latter, that which, whensoever it is present, is secreted in all cases ready-made, is the milk; sperm, on the other hand, is not like [20] that in all cases, but in some only, as in the case of what are designated thori in fishes.
Whatever animals have milk, have it in their breasts. All animals have breasts that are internally and externally viviparous, as for instance all animals that have hair, as man and the horse; and the cetaceans, as the dolphin, the porpoise, and the whale—for these animals have breasts and are supplied with milk. Animals that are [25] oviparous or only externally viviparous have neither breasts nor milk, as the fish and the bird.