Aristotle · a new plain-English translation from the original language
1| The human bladder is of moderate size. The penis is attached to the stalk of the bladder, its outermost opening running together into one, a little below. One of the two openings leads to the testicles, the other to the bladder, and this latter is sinewy and cartilaginous. The testicles are attached to this in males, and how they are arranged will be determined among the topics discussed in common. The same arrangement holds in the female too, in every respect; for she differs in none of the internal parts except the womb, whose appearance should be studied from the diagram in the dissections, and whose position is above the intestines, with the bladder above the womb. We must speak about wombs in general, covering all of them together, in what follows; for they are not alike in all animals nor arranged alike. These, then, and of this kind, are the internal and external parts of man, and this is how they stand. B.
2| Of the other animals, some parts are common to all, as has been said before, while others belong to particular kinds. Parts are the same as one another and different from one another in the way already stated many times. For virtually all animals that differ in genus also have most of their parts differing in species; some parts are undifferentiated only by analogy while differing in genus, others are the same in genus but differ in species; and many parts belong to some animals but not to others. Now the quadrupeds that bear live young have a head and a neck and all the parts found in the head, though each of these parts differs in shape. The lion has a single bone for its neck, not vertebrae; but when opened up its internal parts are in every way like a dog's. The quadruped, live-bearing animals have, instead of arms, front legs — all the quadrupeds do — and those with many toes use them most analogously to hands, since they use them as hands for many purposes. And their left sides are less independently movable than a human's, except in the elephant; the elephant has the joints of its toes less articulated than other animals' feet, and its front legs are much larger.
3| It has five toes, and above its hind legs it has short ankles. It has a trunk of such a kind and size that it serves it in place of hands; for it drinks and eats by reaching this to its mouth, and it reaches it up to its elephant-driver. With this it also uproots trees, and when walking through water it blows through it. At its tip it bends, but does not flex, since that part is cartilaginous. Man alone among the other animals is ambidextrous. What corresponds to the human chest is present, by analogy, in all animals, but is not similar to it: for man's chest is broad, while in the others it is narrow. No animal has breasts on the front of the body except man; the elephant has two breasts, but not on the chest — near the chest. As for the bending of the limbs, both fore and hind, animals have them opposite both to one another and to the bendings of man, except the elephant. For in the quadrupeds that bear live young, the front limbs bend forward and the hind limbs bend backward, and the concave sides of their curvature are turned opposite to each other; but the elephant does not do as some have said, but crouches down and bends its legs, except that because of its weight it cannot do this on both sides at once, but leans over onto its left or its right, and sleeps in this posture, and it bends its hind legs the way a man does.
4| For egg-laying animals, such as the crocodile and the lizard and all others of that kind, both sets of legs, front and back, bend forward, inclining a little to the side. It is the same too with the other many-footed animals; except that the ones lying between the extremes always bend both ways and have their bending more to the side. Man has both bendings of his limbs on the same side, but opposite to each other: for he bends his arms backward — except that they curve a little to the side, inward — while he bends his legs forward. None of the animals bends its front or back limbs backward. In all animals the bending of the shoulder is opposite to that of the elbow and the front legs, and the bending of the hip is opposite to that of the hind knee; so that, since man bends contrary to most animals, those animals that have limbs like his also bend contrary to the rest. The bird has bendings similar to those of the four-footed animals: for being two-footed, it bends its legs backward, and instead of arms and front legs it has wings, whose bending is forward.
5| The seal is, as it were, a maimed four-footed animal: for right after the shoulder-blade it has feet like hands, just as bears do too; for they are five-toed, and each of the toes has three bendings and a claw that is not large; the hind feet are likewise five-toed, and have bendings and claws similar to the front ones, but in shape they are similar to the tails of fish. The movements of the four-footed and many-footed animals go along the diagonal, and that is how they stand as well; and in all of them the initiation comes from the right side. The lion walks leg-following-leg, and so do both kinds of camel, the Bactrian and the Arabian. Walking leg-following-leg means that the right foot does not step out ahead of the left, but follows it. The four-footed animals have, on their underside, the parts that man has in front, and on their upper side the parts that are in back with him. Further, most of them have a tail; for even the seal has a small one, similar to a deer's. About the ape-like animals a determination will be made later. All that are four-footed and bear their young live are, one might say, shaggy, and not like man, who has little hair and fine hair, except on the head — the head being the shaggiest part of any animal.
6| Further, in the other animals that have hair, the back parts are shaggier, while the underside is either altogether smooth or less shaggy; man is the opposite. And man has eyelashes on both lids, and has hair in the armpits and on the pubic region; none of the other animals has either of these, nor a lower eyelash, but in some, below the eyelid, sparse hairs grow. Among the four-footed animals that have hair, in some the whole body is shaggy, as with the pig, the bear, and the dog; others are shaggier on the neck uniformly all around, namely those that have a mane, like the lion; others are shaggy on the back of the neck from the head down to the top of the shoulder, namely those that have a crest, like the horse and the mule, and, among the wild horned animals, the bison. The animal called the hippelaphos also has a mane at the top of the shoulder, and so does the beast called the pardion; from the head to the top of the shoulder each has a thin one, and the hippelaphos alone has, besides, a beard along the throat. Both are horned and cloven-hoofed; the female hippelaphos has no horns. This animal is close in size to the deer.
7| Hippelaphoi occur in Arachotia, the same place where the wild oxen also occur. The wild ones differ from the tame just as wild pigs differ from tame pigs: for they are black and powerful in appearance and hook-nosed, and their horns curve back more sharply; the horns of the hippelaphoi are similar to those of the gazelle. The elephant is the least shaggy of the four-footed animals. In those whose tails have any size, the tails follow the rest of the body in shagginess or smoothness; for some have altogether small tails. Camels have, unlike the other four-footed animals, what is called a hump on the back. The Bactrian camels differ from the Arabian: the former have two humps, the latter only one, but they have another hump of the sort that lies, as it were, above the lower one, on which, when the camel kneels down onto its knees, the rest of the body is propped. The camel has four teats, like the ox, and a tail similar to the donkey's, and its genitals point backward. It has one knee in each leg, and not more bendings than that, as some say — it only appears so because of the way the belly hangs down beneath it.
8| And it has an ankle-bone similar to the ox's, but slender and small for its size. It is cloven-hoofed and does not have teeth in both jaws; it is cloven in the following way. From behind it is split a little, as far as the second bending of the toes; in front it is split only a little, as far as the first bending of the toes, four splits at the very tip; and there is also something running through the middle of the splits, as with geese. The foot is fleshy underneath, as the feet of bears also are; and this is why they fit rawhide shoes onto the camels that go to war, whenever their feet are sore. All the four-footed animals have legs that are bony and sinewy and without flesh; and in general so do all the other animals that have feet, except man. They are also without buttocks; and indeed birds are affected by this even more. Man is the opposite: he has, of practically his whole body, the fleshiest parts in his hips and thighs and shins; for the so-called calves in the shins are fleshy. Among the four-footed, blooded, live-bearing animals, some are many-toed, like the hands and feet of man (for some are many-toed, such as the dog, the lion, and the leopard), others are two-toed, and instead of claws have hooves, like the sheep, the goat, the deer, and the river-horse;
9| and others are not cloven at all, namely the solid-hoofed, like the horse and the mule. The pig kind goes both ways: for there are, in Illyria and in Paeonia and elsewhere, solid-hoofed pigs as well. Now the cloven-hoofed have two splits behind; but in the solid-hoofed this is continuous. Again, some animals are horned, others hornless. Most of those that have horns are by nature cloven-hoofed, such as the ox, the deer, and the goat; but nothing solid-hoofed and two-horned has been observed by us. Few are one-horned and solid-hoofed, such as the Indian ass. The oryx is one-horned and cloven-hoofed. And the Indian ass alone, among the solid-hoofed, has an ankle-bone; for the pig, as was said before, goes both ways, and for that reason it does not have a well-formed ankle-bone either. Of the cloven-hoofed, many have an ankle-bone. No many-toed animal has been observed to have such a bone, nor does man; but the lynx has one similar to a half ankle-bone, while the lion has one like a labyrinth, of the sort sculptors represent. All that have an ankle-bone have it in the hind legs. The ankle-bone stands upright at the joint, with its convex side facing outward and its concave side facing inward; the faces called "Coan" are turned inward toward each other, while those called "Chian" face outward, and the projecting ridges point upward.
10| The position of the ankle-bones, then, is this same way in all the animals that have them. There are some animals that are cloven-hoofed and at the same time have a mane and two horns bent in toward each other, for example the bonasus, which occurs around Paeonia and Maedica. All horn-bearing animals are four-footed, unless something is said to have a horn by a transfer of the word, as for example the Egyptians say the snakes around Thebes have, these having a projection that serves only as a kind of pretext to the name. Of the animals that have horns, only the deer has a horn that is solid all the way through; the others are hollow up to a point, and the extremity alone is solid. The hollow part grows more from the skin, and around this the solid part, made of bone, is fitted, as with the horns of oxen. Only the deer sheds its horns, yearly, beginning from the age of two, and grows them again; the others keep theirs continuously, unless one is maimed by some force. Further, with respect to the breasts there is a difference among the other animals, both compared with each other and compared with man, and likewise with respect to the organs useful for mating. For some have their breasts in front, on the chest or near the chest, and have two breasts and two nipples, as man and the elephant do, as has been said before.
11| For the elephant too has its two breasts near the armpits; and the female has breasts that are altogether small and not in proportion to the size of her body, so that from the side one can hardly see them at all; the males too have breasts, like the females, altogether small. The bear has four. Some animals have two breasts, but have them on the thighs, and two nipples as well, like the sheep; others have four nipples, like the ox. Others have their breasts neither on the chest nor on the thighs, but on the belly, for example the dog and the pig, and these have many, though they are not all equal. Most of the others have more, but the leopard has four on the belly, and the lioness has two on the belly. The camel too has two breasts and four nipples, like the ox. Among the solid-hoofed animals the males do not have breasts, except such as resemble their mother, which is what happens with horses. As for the genitals, the males have them external in some cases, as man and the horse and many others, and internal in others, as the dolphin;
12| and among those that have them external, some have them turned forward, as in the cases mentioned, and of these some have both the member and the testicles separate and free, as man does, while others have both the testicles and the member attached to the belly, and some are more free and others less so; for this part is not equally free in the boar and in the horse. The elephant too has a member similar to the horse's, but small and not in proportion to the size of its body, and its testicles are not visible externally but are internal, near the kidneys; this is also why it finishes mating quickly. The female has her genital organ in the place where the udders of sheep are. When she is in heat to be mated, she draws it upward and turns it out toward the outer region, so that mating is easy for the male; and the genital organ is split open fairly extensively. In most animals, then, the genitals are arranged in this way; but some urinate backward, for example the lynx and the lion and the camel and the hare. The males, then, are opposed to one another in this respect, as has been said, but all the females urinate backward;
13| for the female elephant too has her genitals under the thighs, just as the other female animals do. There is much difference among genital organs. Some have a genital organ that is cartilaginous and fleshy, as man does; the fleshy part cannot be inflated, but the cartilaginous part is capable of increase. Others have sinewy ones, as the camel and the deer, and others bony ones, as the fox and the wolf and the marten and the weasel; for the weasel too has a bone in its genital organ. Beyond this, man, once fully grown, has the upper parts smaller than the lower, while the other animals, all those that have blood, have the opposite. By the upper parts we mean everything from the head down to the part where the residue has its exit, and by the lower parts what remains from there on. In the animals that have feet, the hind leg is the lower part relative to the body's size; in those without feet there are tails and rumps and the like instead. This, then, is how they are when fully grown, but they differ in the course of growth: for man, while young, has the upper parts larger than the lower, but as he grows he changes to the opposite (which is also why, virtually alone, he does not make the same manner of movement in walking when young and when full-grown, but as an infant he creeps on all fours at first), whereas other animals keep their growth in proportion, for example the dog.
14| Some animals have the upper parts smaller at first and the lower parts larger, but as they grow the upper parts become larger, as with the maned animals; for in none of these does the part from the hoof to the hip-joint ever become larger later on. There is also much difference with respect to the teeth among the other animals, both compared with one another and compared with man. All four-footed, blooded, live-bearing animals have teeth, but to begin with, some have teeth in both jaws and some do not. All horn-bearing animals do not have teeth in both jaws; for they do not have front teeth in the upper jaw. But there are some that lack teeth in both jaws and yet are also hornless, for example the camel. Some have tusks, as the male pigs do, and some do not. Further, some of them are saw-toothed, as the lion and the leopard and the dog, while others have teeth that do not interlock, as the horse and the ox; for saw-toothed animals are those whose sharp teeth overlap one another. No animal has both tusks and horns at once, nor is any animal both saw-toothed and either of these. Most animals have their front teeth sharp and their inner teeth broad. The seal is saw-toothed in all its teeth, as if it overlapped with the class of fishes; for nearly all fish are saw-toothed. None of these kinds has a double row of teeth. But there is, if one is to trust Ctesias; for he says that the beast among the Indians called the martichora has, on each side, three rows of teeth;
15| and that it is in size equal to a lion and similarly shaggy, and has feet like a lion's, but a face and ears like a man's, and its eye is blue-grey, and its color cinnabar-red, and its tail like that of the land scorpion, in which it has a sting and shoots out its barbs, and its voice is like the sound of a pipe and a trumpet together, and it runs no less swiftly than deer, and is savage and man-eating. Man, then, sheds his teeth, and so do other animals as well, for example the horse and the mule and the donkey. Man sheds his front teeth, but no animal sheds its molars. The pig sheds none of its teeth at all. Concerning dogs there is dispute, and some think they do not shed any teeth at all, while others think they shed only the canine teeth; but it has been observed that they shed teeth just as man does, though this escapes notice because they do not shed them until an equal number have grown up underneath beforehand. It is likely that the same thing happens with the other wild animals as well, since they too are said to shed only their canine teeth. People distinguish younger from older dogs by their teeth: the young ones have teeth that are white and sharp, the older ones have teeth that are black and blunt.
16| With horses the opposite happens compared with the other animals: for the other animals, as they grow older, have blacker teeth, but the horse has whiter ones. The teeth called canines mark the boundary between the sharp and the broad teeth, sharing in the shape of both: for they are broad at the bottom and sharp at the top. Males have more teeth than females, both in human beings and in the case of sheep, goats, and pigs; in the other animals this has not yet been observed. Those that have more teeth are, for the most part, longer-lived, while those with fewer and more widely spaced teeth are, for the most part, shorter-lived. The last teeth to grow in human beings are the molars called the wisdom teeth, which come in around the age of twenty in both men and women. Already in some women even as old as eighty, wisdom teeth have grown in at the very end, causing pain as they came up, and likewise in men; this happens to those in whom the wisdom teeth did not come up during the proper age. The elephant has four teeth on each side, with which it processes its food (it grinds it fine like groats), and apart from these, two other large teeth. The male has these large and curving upward, while the female has small ones pointing the opposite way from the male's; for hers point downward. The elephant has teeth as soon as it is born, though the large ones are at first not visible.
17| Its tongue is very small and set far inside, so that it is hard work to see it. Animals also differ in the size of the mouth. Some have mouths that are split wide open, as with the dog and the lion and all the sharp-toothed animals; others have small mouths, as man does; and others are in between, as with the pig kind. The river horse in Egypt has a mane like a horse, but is cloven-hoofed like an ox, and snub-faced in appearance. It also has an ankle-bone like the cloven-footed animals, and tusks showing slightly, a tail like a pig's, and a voice like a horse's; it is the size of a donkey. Its hide is so thick that spear-shafts are made from it. Its internal organs are like those of a horse and a donkey.
18| Some animals are ambiguous in nature between man and the four-footed animals, for example monkeys, cebi, and baboons. The cebus is a monkey with a tail. Baboons have the same shape as monkeys, except that they are larger and stronger, with faces more doglike, and further, they have wilder characters and teeth that are more doglike and stronger. Monkeys are hairy on their backs, since they are four-footed, and likewise on their fronts, since they are shaped like human beings (for in human beings this is the reverse of what holds in four-footed animals, as was said before); except that the hair is coarse, and monkeys are very hairy on both sides. Its face has many resemblances to that of a human being: it has nostrils and ears much like ours, and teeth like a human's, both the front teeth and the molars. Further, whereas the other four-footed animals lack eyelashes on one of the two lids, this animal has them, though very thin ones, and more on the lower lid, and altogether small; for the other four-footed animals do not have these at all. It has on its chest two nipples with small breasts.
19| It also has arms like a human being, except hairy; and it bends these and its legs just as a human being does, with the bends of both limbs turned toward each other. In addition to these it has hands, fingers, and nails like a human being's, except that all these are more brutish. Its feet are peculiar to it: for they are like large hands, and the toes are like fingers, the middle one being the longest, and the underside of the foot is like a hand, except that it is drawn out lengthwise toward the extremity like the hand is, corresponding to the palm; and this part is harder at the tip, poorly and faintly imitating a heel. It uses its feet for both purposes, both as hands and as feet, and it flexes them together as it does its hands. Its forearm and thigh are short in relation to its upper arm and shin. It has no protruding navel, but the place where the navel would be is hard. Its upper parts are much larger than its lower parts, as with the four-footed animals; the ratio is roughly five to three. And because of this, and also because its feet are like hands and seem to be composed, as it were, out of a hand and a foot — out of a foot as regards the extreme end at the heel, and out of a hand as regards the other parts —
20| for its toes too have what is called a palm. It spends most of its time going on four feet rather than upright; and it has neither haunches, as a four-footed animal would, nor a tail, as a two-footed animal would, except a small one altogether, just enough to serve as a mark. The female also has genitals like a woman's, while the male's are more doglike than a human's. The cebi, as was said before, have a tail. Their internal organs, when dissected, are all like a human being's in such respects. This, then, is the character of the parts of those animals that bear their young alive to the outside.
21| The four-footed animals that are egg-laying and blooded (and nothing that is land-dwelling and blooded lays eggs unless it is four-footed or footless) have a head, a neck, a back, and the front and rear surfaces of the body, and further, front legs and hind legs and something corresponding to the chest, as the live-bearing four-footed animals do, and a tail — larger in most cases, smaller in a few. All such animals are many-toed and many-clawed. Further, they all have the sense organs and a tongue, except the crocodile in Egypt. This one is in a condition like that of certain fish: for fish in general have a tongue that is spiny and not free, and some have a place that is altogether smooth and unarticulated unless the lip is bent well back. Such animals have no ears, only the passage for hearing, all of them; nor breasts, nor genitals, nor testicles visible outside but only within, nor hair, but they are all covered with scales. Further, they are all sharp-toothed. River crocodiles have eyes like a pig's, large teeth including tusks, strong claws, and an unbreakable scaly hide; they see poorly in the water but extremely sharply out of it. They spend most of the day on land and the night in the water; for the water is warmer than the open air.
22| The chameleon has a body whose overall shape is lizard-like, but its ribs come down to meet the belly, as with fish, and its spine stands up in a ridge as fish's do. Its face is most like that of a small long-tailed monkey. It has a very long tail, tapering to a fine point and coiling up over much of its length, like a strap. It stands higher off the ground than lizards do, but the bends of its legs are like those of lizards. Each of its feet is divided in two into parts that stand in the same relation to each other as our big toe does in opposition to the rest of the hand. Each of these parts is in turn divided a little way into several toes: on the front feet, three toes point inward and two outward; on the hind feet, two point inward and three outward. It also has small claws on these, like those of the hook-taloned birds. Its whole body is rough, like the crocodile's. Its eyes are set in a hollow, very large and round, and enclosed by skin like the rest of the body.
23| Right through the middle of them a small space is left for sight, through which it sees; the skin never covers this. It turns the eye in a circle and shifts its gaze to every region, and in this way sees whatever it wants. The change of color happens to it when it is inflated; and it has a black color, not far from that of crocodiles, and a pale one like lizards, mottled with black like leopards. This kind of change occurs over its whole body; for the eyes change along with it, in the same way as the rest of the body, and so does the tail. Its motion is extremely sluggish, like that of tortoises. When it is dying it turns pale, and once it has died its color stays like that. The parts around the gullet and windpipe are arranged in the same way as in lizards. It has flesh nowhere except a little near the head and jaws, and around the base of the tail. And it has blood only around the heart and the eyes and the region above the heart, and whatever small veins extend from these; and even in these there is altogether little.
24| The brain lies a little above the eyes, and is continuous with them. When the outer skin of the eyes is stripped away, it contains something shining through, like a thin ring of bronze. Over almost its whole body strong membranes stretch, many of them, and greatly exceeding those found in other animals. It goes on functioning by its breath, even when cut open all over, for a long time, while a very slight motion still remains in it around the heart; and it contracts most notably the parts around the ribs, though the rest of the body's parts as well. It has no spleen anywhere visible. It hibernates like lizards.
25| Birds, too, have some parts similar to those of the animals mentioned; for all of them have a head and a neck and a back and the underside of the body and the part analogous to the chest; and two legs, like man more than any other animal, except that they bend them backward as the four-footed animals do, as was said before. They have neither hands nor forefeet, but wings, which are peculiar to them among other animals. Further, the hip is like a long thigh and is attached down to below the middle of the belly, so that when divided it appears to be a thigh, while the actual thigh, lying between it and the shank, is a distinct part. The birds with hooked talons have the largest thighs, and their chest is stronger than that of the others. All birds have many claws, and in a sense all are many-cleft; for in most of them the toes are separated, while the swimming ones are web-footed, though they too have jointed and separate toes. All those that fly up into the air have four toes: most have three set forward and one set behind in place of a heel; but a few have two forward and two behind, such as the bird called the wryneck.
26| This bird is a little larger than a finch, of mottled appearance, and has peculiarities both in its toes and in its tongue, which is like that of snakes; for it stretches out lengthwise to four finger-breadths and then draws back into itself again. Further, it twists its neck backward while the rest of the body stays still, just as snakes do. Its claws are large but grown in the same way as those of jackdaws; and in voice it makes a shrill cry. Birds have a mouth, but a peculiar one: they have neither lips nor teeth, but a beak; and neither ears nor nostrils, but the passages for these senses — the passage for smell in the beak, that for hearing in the head. All of them, like the other animals, have two eyes, without eyelashes. The heavy-bodied ones close the lower eyelid, and all of them blink with a skin that comes from the corner of the eye, while the grey-eyed birds also use the upper eyelid. The scaly animals do the same thing, such as lizards and the other animals of the same kind as these; for all of them close with the lower eyelid, though they do not blink as birds do.
27| Further, they have neither scales nor hair, but feathers; and every feather has a shaft. They do not have a tail properly speaking, but a rump: the long-legged and web-footed ones have a short one, the opposite kind a large one. And these latter fly with their feet held against the belly, while those with a small rump fly with their feet stretched out. All have a tongue, but it is not alike in all: some have a long one, others a broad one. Of the animals after man, some kinds of birds most articulate distinct sounds; and it is above all the broad-tongued ones among them that do this. None of the egg-laying animals has an epiglottis on the windpipe, but instead it draws together and opens the passage, so that nothing heavy is let down onto the lung. Some kinds of birds also have spurs; but none has hooked talons and a spur together. The hook-taloned belong among the birds of strong flight, the spur-bearing among the heavy-bodied ones. Further, some birds have a crest: in some of these it is made of the feathers themselves standing up, but the cock alone has one of its own peculiar kind; for it is neither flesh nor, in its nature, far from flesh.
28| Among the water animals the class of fish is marked off as a single kind from the rest, though it contains many forms within it. It has a head, and a front and a back, in the region of which lie the belly and the internal organs; and it has a hindmost tail part that is continuous and undivided, though this is not alike in all. No fish has a neck, nor any limb at all, nor testicles whatsoever, either internal or external, nor breasts. This holds altogether, and likewise for every other animal that does not bear live young — nor even for all that do bear live young, but only for those that produce live young directly within themselves and do not first lay eggs. For the dolphin bears live young, and for this reason it has two breasts, not above but near the joints. It does not have projecting teats as the four-footed animals do, but as it were two channels, one on each side from the flanks, from which the milk flows; and it is suckled by its young as they swim alongside; and this has already been clearly observed by some. Fish, as has been said, have neither breasts nor any visible external passage for the genitals. What is peculiar to them is the matter of the gills, by which they let out the water they take in through the mouth, and the fins — most having four, but the elongated ones two, such as the eel, situated near the gills.
29| Similarly also the grey mullets, such as those in the lake at Siphae, have two, and likewise the fish called the ribbon-fish. Some of the elongated ones do not even have fins, such as the moray eel, nor gills articulated in the same way as in the other fish. Among those that do have gills, some have coverings over the gills, while all the cartilaginous fish have them uncovered. And all those with coverings have their gills set sideways, while among the cartilaginous fish the flat ones have them below, on their underside, such as the torpedo fish and the ray, but the elongated ones have them on the sides, such as all the dogfish kind. The angel-fish has them sideways, but covered not with a spiny covering as the non-cartilaginous fish are, but with a skin-like one. Further, among those that have gills, some have simple gills, others double ones; but in all of them the last one, nearest the body, is simple. And again, some have few gills, others a great number; but all have equal numbers on each side. The one with the fewest has one gill on each side, and this a double one, such as the boar-fish; others have two on each side, one simple and one double, such as the conger eel and the parrotfish;
30| Others have four simple gills on each side, for example the elops, the dentex, the moray, the eel. Others have four gills, double except for the last, for example the thrush-fish, the perch, the sheat-fish, and the carp. The dogfish tribe all have double gills, five on each side; the swordfish has eight, all double. This, then, is how matters stand regarding the number of gills among fish. Further, fish differ from the other animals in more than just this matter of the gills: they do not, as land animals that bear their young alive have hair, nor as some of the egg-laying quadrupeds have horny scales, nor as the tribe of birds is feathered; rather most of them are covered with scales, a few are rough-skinned, and the smallest number of all are smooth. Among the cartilaginous fish, some are rough and some smooth; conger eels, eels, and tunnies belong among the smooth ones. All fish are saw-toothed except the parrot-fish; and all have sharp teeth set in many rows, and some have them on the tongue as well. Their tongue is hard and spiny, and so firmly grown to the mouth that at times it does not seem to have one at all. As for the mouth, in some it is split wide open, as in some of the live-bearing quadrupeds.
31| Of the other sense organs they show no visible trace, neither the organ itself nor its passages, either for hearing or for smell; but all have eyes, without eyelids, though their eyes are not hard-surfaced. The whole class of fish, then, has blood; and of them some are egg-layers and some bear their young alive — all the scaly ones are egg-layers, while all the cartilaginous fish bear their young alive, except the fishing-frog.
32| What remains among the blooded animals is the tribe of serpents. This tribe is shared between land and water: most of them are land-dwellers, but a small portion of the water-dwelling kind spends its life in fresh water. There are also sea-serpents, similar in shape to the land ones in every other respect, except that their head is more conger-like. There are many kinds of sea-serpents, and they have every sort of coloring; these do not occur in very deep water. Serpents are footless, like the tribe of fish. There are also sea-centipedes, similar in form to the land ones but somewhat smaller in size; they occur around rocky places. In color they are redder, and they have more legs and thinner legs than the land ones. These too, like the serpents, do not occur in very deep water. There is a certain small rock-fish that some people call the remora, and some use it for lawsuits and love-charms; it is not eaten. Some say it has feet, though it does not, but it appears to because its fins are shaped like feet. So much, then, has been said about the external parts of the blooded animals — how many they are, of what kind, and what differences they show from one another.
33| What must next be discussed, in the case of the blooded animals first, is the condition of their internal parts; for it is by this that the largest classes differ most from the rest of the other animals — by some being blooded and others bloodless. The blooded animals are man and the live-bearing quadrupeds, and further the egg-laying quadrupeds, and bird, and fish, and cetacean, and whatever else has no name because it does not form a genus but is a single species among individual kinds, for example the serpent and the crocodile. Now all animals that are quadrupeds and bear their young alive have both a gullet and a windpipe, positioned in the same way as in man; and likewise so do the egg-laying quadrupeds, and the birds too — though they differ from one another in the forms of these parts. And in general, all animals that draw in air and breathe it in and out have a lung and a windpipe and a gullet, and the position of the gullet and the windpipe is similar in all, though the parts themselves are not alike; but the lung is neither alike in form nor similarly positioned in all. Further, all animals that have blood have a heart, and also the partition, which is called the midriff;
34| but in small animals, on account of its thinness and smallness, it is not equally visible, except in the case of the heart. A peculiar thing occurs in oxen: there is a certain kind of ox — not all of them — that has a bone in its heart. The horse's heart also has a bone. Not all animals have a lung; fish do not have one, nor does any other animal that has gills. All animals that have blood have a liver. Most animals that have blood also have a spleen. Many of those that do not bear their young alive but lay eggs have so small a spleen that it nearly escapes notice — this is so among most birds, for example the pigeon, the kite, the hawk, and the owl; the vulture has none at all. And among the egg-laying quadrupeds the same holds: they have altogether tiny spleens, for example the tortoise, the terrapin, the toad, the lizard, the crocodile, and the frog. Of animals, some have gall attached to the liver and some do not. Among the live-bearing quadrupeds, the deer has none, nor does the roe; nor, further, does the horse, the mule, the donkey, the seal, and some of the swine.
35| Among deer, the kind called the Achainai seem to have gall in their tail; what is said is that its color resembles gall, though it is not so entirely liquid, but is rather like the outer part of the spleen. All deer, however, have living worms in the head; these arise below the part under the tongue, in the hollow near the vertebra to which the head is attached, and are not smaller in size than the largest maggots; they arise in a mass and packed close together, and number about twenty at most. Deer, then, do not have gall, as has been said; and their intestine is so bitter that even dogs are unwilling to eat it, unless the deer is extremely fat. The elephant too has a liver without gall, yet when a cut is made near the spot where, in animals that have it, the gall grows on, a bilious fluid runs out, in greater or lesser amount. Among the sea-dwelling animals that have a lung, the dolphin has no gall. Birds and fish all have it, and so do the egg-laying quadrupeds — as a general rule, in greater or lesser amount; but in fish some have it attached to the liver, for example the dogfish tribe, the sheat-fish, the ray, the smooth ray, the electric ray, and among the long fish the eel, the garfish, and the hammerhead shark.
36| The stargazer also has it on the liver, and this fish has the largest gall of any fish relative to its size. Others have it near the intestines, stretched away from the liver by certain very thin ducts. The bonito has it stretched alongside the intestine, of equal length, and often even doubled back; others have it near the intestines, some farther off and some nearer, for example the fishing-frog, the elops, the dentex, the moray, and the swordfish. Often the same kind is found to have it in both positions, for example conger eels — some have it near the liver, others have it suspended below. The same holds for birds as well: some have the gall near the stomach, others near the intestines, for example the pigeon, the raven, the quail, the swallow, and the sparrow. Some have it both near the liver and near the stomach at once, for example the vulture; others have it both near the liver and near the intestines at once, for example the hawk and the kite. As for kidneys and bladder, all the live-bearing quadrupeds have them; of the egg-laying animals, none of the others have them, neither bird nor fish, but among the quadrupeds only the sea-tortoise has them, of a size proportionate to its other parts. The sea-tortoise has kidneys similar to those of oxen; the ox's kidney is, as it were, made up of many small ones joined into one. The bison too has all its internal parts similar to the ox's.
37| As for position, all animals that have these parts have them positioned alike, with the heart around the middle, except in man; in man it lies more toward the left, as was said before. And in all animals the heart has its point turned forward, except that in fish this would not seem to be so; for their point is not turned toward the chest, but toward the head and mouth. The tip of the heart is attached at the point where the right and left gills join one another. There are also other passages stretching from the heart to each of the gills, larger in the larger fish and smaller in the smaller ones; and the one at the very tip of the heart, in the large fish, is an extremely thick white tube. Few fish have a gullet, for example the conger eel and the eel, and in these it is small. As for the liver, in those animals whose liver is undivided, it lies wholly on the right side; in those whose liver is divided from the start, the larger part is on the right. For in some animals each of the two parts hangs separately and the two do not grow together at their origin, as in the cartilaginous fish among fishes, and in a certain kind of hare found elsewhere and also around Lake Bolbe in the place called Sycine, which one might suppose to have two livers because their ducts join only far apart, just as also happens with the lung of birds.
38| The spleen too lies, in all animals, naturally on the left, and the kidneys, in those that have them, lie in the same manner; though one four-footed animal has already been observed, on dissection, to have its spleen on the right and its liver on the left — but such cases are judged to be monstrosities. The windpipe stretches, in all animals, to the lung (in what manner we will say later), and the gullet, in those that have one, stretches to the stomach through the diaphragm; for most fish, as was said before, do not have a gullet, but the stomach joins directly onto the mouth, so that often, in some of the large fish chasing smaller ones, the stomach is thrust forward out through the mouth. All the animals mentioned have a stomach, and it is positioned alike in all of them (for it lies immediately below the diaphragm), and the intestine is continuous with it and ends at the exit for the food, at what is called the anus. But their stomachs are not alike. First, among the four-footed and live-bearing animals, all those horned animals that do not have teeth in both jaws have four such passages; and these are the animals said to chew the cud. For the gullet, beginning at the mouth, runs down past the lung, and from the diaphragm on to the large stomach;
39| and this stomach has rough, partitioned walls on the inside. Near where the gullet enters it, there is attached to it what is called, from its appearance, the honeycomb-bag; for on the outside it resembles the stomach, but on the inside it resembles woven honeycombs; in size the honeycomb-bag is much smaller than the stomach. Next to this comes the many-plied stomach, rough and plate-like on the inside, about the same size as the honeycomb-bag. After this comes what is called the reed, larger than the many-plied stomach and more elongated in shape; it has inside it many large smooth plates. From this the intestine then begins. Such, then, is the stomach of the horned animals that do not have teeth in both jaws; but they differ from one another in the shapes and sizes of these parts, and in whether the gullet enters the middle or the side of the stomach. The animals with teeth in both jaws have a single stomach, for example man, pig, dog, bear, lion, wolf. The jackal too has all its internal organs like the wolf's. All these, then, have a single stomach, and after it the intestine; but some have a larger stomach, like the pig and the bear (and the pig's has a few smooth plates), while others have a much smaller one, not much larger than the intestine, as with the dog, the lion, and man.
40| And the species of the other animals divide up in relation to these two kinds of stomach; some have one like the pig's, others one like the dog's, and this holds equally for the larger and the smaller animals. There is also variation among these in the size, shape, thickness, and thinness of the stomach, and in the position at which the gullet pierces into it. The nature of the intestines also differs between the two kinds of animal mentioned, those without teeth in both jaws and those with, in size, thickness, and the number of their coils. In all cases the intestines of the animals without teeth in both jaws are larger; for these animals themselves are all larger — few horned animals are small, and none at all is very small. Some animals also have outgrowths from their intestines, and no animal without teeth in both jaws has a straight intestine. The elephant has an intestine with internal partitions, so that it appears to have four stomachs. It is in this intestine that the food is processed, and apart from it the elephant has no separate stomach organ. Its internal organs are similar to the pig's, except that its liver is four times the size of an ox's liver, and the other organs correspondingly, while its spleen is smaller than proportion would suggest. The stomach and the nature of the intestines are the same, in the same way, also in those four-footed but egg-laying animals, such as the land tortoise and the sea turtle, the lizard, and both kinds of crocodile, and in all similar animals generally;
41| for they too have a simple, single stomach, and in some it resembles the pig's, in others the dog's. The class of snakes is similar and has almost everything in common with the land, egg-laying lizards, if one grants them length and takes away their feet. For a snake is scaly, and its upper and lower surfaces resemble those of lizards; except that it has no testicles, but instead, like a fish, two ducts joining into one, and a womb that is long and forked. The rest of its internal organs are the same as the lizard's, except that all of them, owing to the narrowness and length of the body, are narrow and elongated, so that their resemblance to the lizard's organs is not obvious at a glance; for its windpipe is very long, and its gullet is even longer still. The windpipe begins right at the mouth itself, so that the tongue seems to lie beneath it. The windpipe seems to project beyond the tongue because the tongue is drawn back and does not stay extended as it does in other animals. The tongue is thin, long, and black, and can be put out to a great distance. Snakes and lizards have, as something peculiar compared to the tongues of other animals, a tip that is forked, and this is far more pronounced in snakes;
42| for the tips of a snake's tongue are as thin as hairs. The seal too has a split tongue. The snake's stomach is like a wider intestine, resembling the dog's; after it comes the intestine, which is long and thin and remains a single tube to the end. The heart lies at the throat, and is small and kidney-shaped; this is why it might sometimes seem that its point is not turned toward the chest. Next comes the lung, which is single, divided by a fibrous passage, and very long, lying far apart from the heart. The liver too is long and simple, and the spleen is small and round, as in lizards as well. Snakes have bile in the same way as fish do; for water-snakes have it attached to the liver, while the others generally have it near the intestines. All snakes have saw-like teeth. They have ribs equal in number to the days of the month, for they have thirty. Some say that the same thing happens with snakes as with the nestlings of swallows: they say that if one pricks out the eyes of snakes, they grow back again. And the tails of both lizards and snakes, when cut off, grow back.
43| It is the same way with fish as regards the intestines and the belly: they have a single simple gut, but it differs in shape. For some have an intestine that is completely gut-like throughout, such as the fish they call the parrotfish, which indeed seems to be the only fish that chews the cud. And the size of the intestine is uniform, and it has a fold back on itself, which unwinds into one straight length. It is peculiar to fish and to most birds to have blind appendages; but birds have them below and few in number, while fish have them above, near the belly, and some have many, such as the goby, the dogfish, the perch, the scorpion fish, the citharus, the red mullet, the sea bream. The grey mullet has many on one side of the belly but only one on the other. Some have them but few, such as the liver-fish and the grey fish; and the gilt-head also has few. And they differ even from themselves: for instance, one gilt-head has more, another fewer. And there are some that have none at all, such as most of the cartilaginous fish; of the rest, some have few, and some have very many. All fish have these appendages right at the belly itself. Birds differ from one another, and from the other animals, with regard to their internal parts.
44| Some birds have a crop in front of the belly, such as the cock, the ring-dove, the pigeon, the partridge. The crop is a hollow, large skin, in which the food, on first entering, is still undigested. At the point where it joins the gullet it is narrower, then it becomes wider, and where it in turn opens down into the belly it becomes thinner again. Most birds have a belly that is fleshy and firm, with a strong skin inside that can be peeled away from the flesh. Others do not have a crop, but instead have a gullet that is wide and broad, either along its whole length or in the part that stretches toward the belly, such as the jackdaw, the raven, and the crow. The quail also has the wide part of its gullet lower down, and the goatsucker and the owl have the lower part somewhat wider. The duck, the goose, the gull, the cormorant, and the bustard have the whole gullet wide and broad, and many other birds are the same. Some have something belly-like resembling a crop, such as the kestrel. There are some that have neither a wide gullet nor a crop, but instead a long belly — this is true of the small birds, such as the swallow and the sparrow.