Aesop's Fables [6th century BCE +] (The Beaver; Perry 118) There is an animal whose name in English is 'beaver' (although those garrulous Greeks -- so proud of their endless supply of words! -- call him castor, which is also the name of a god). It is said that when the beaver is being chased by dogs and realizes that he cannot outrun them, he bites off his testicles, since he knows that this is what he is hunted for. I suppose there is some kind of superhuman understanding that prompts the beaver to act this way, for as soon as the hunter lays his hands on that magical medicine, he abandons the chase and calls off his dogs. - [ Gibbs translation]

Pliny the Elder [1st century CE] (Natural History, Book 8, 47): The beavers of the Black Sea region practice self amputation of the same organ when beset by danger, as they know that they are hunted for the sake of its secretion, the medical name for which is beaver-oil. Apart from this the beaver is an animal with a formidable bite, cutting down trees on the river banks as if with steel; if it gets hold of part of a man's body it does not relax its bite before the fractured bones are heard grinding together. The beaver has a fish's tail, while the rest of its conformation resembles an otter's; both species are aquatic, and both have fur that is softer than down. - [Rackham translation]

Aelianus [170-230 CE] (On the Characteristics of Animals, Book 6, chapter 34): The Beaver is an amphibious creature: by day it lives hidden in rivers, but at night it roams the land, feeding itself with anything that it can find. Now it understands the reason why hunters come after it with such eagerness and impetuosity, and it puts down its head and with its teeth cuts off its testicles and throws them in their path, as a prudent man who, falling into the hands of robbers, sacrifices all that he is carrying, to save his life, and forfeits his possessions by way of ransom. If however it has already saved its life by self-castration and is again pursued, then it stands up and reveals that it offers no ground for their eager pursuit, and releases the hunters from all further exertions, for they esteem its flesh less. Often however beavers with testicles intact, after escaping as far away as possible, have drawn in the coveted part, and with great skill and ingenuity tricked their pursuers, pretending that they no longer possessed what they were keeping in concealment. - [Scholfield translation]

Gaius Julius Solinus [3rd century CE] (De mirabilibus mundi / Polyhistor, Chapter 13.2): Throughout the whole of Pontus are a great number of beavers, which they call by another name, “castores”. The beaver is similar to an otter, and is a very powerful animal by reason of its bite. When it attacks a man, it does not relax the gnash of its teeth until it senses the snap of breaking bones. Their testicles are sought after for their healing properties. Thus, when the beaver understands himself to be hemmed in, lest his capture be useful to someone, he devours his own “twins”. - [Arwen Apps translation, 2011]

Isidore of Seville [7th century CE] (Etymologies, Book 12, 2:21): The beaver (castor) is so named from being castrated. Beavers are hunted for their testicles, which are good for medicine; when a hunter comes near they bite off their testicles to save themselves. Beavers are also called Pontic dogs.

Gerald of Wales [c. 1146 – c. 1223] (Topographia Hibernica, chapter 21): When they are building their fortress in the bed of a river, they make servants of some of their own species and use them as vehicles in a very extraordinary manner, for collecting and conveying oak boughs from the woods to the water. In both these kinds of animals, some of these servants are to be found remarkable both for their degeneracy and uncouth shape, and for the manner in which the shaggy fur on their backs has been rubbed and worn off. ... It must be noted that beavers have broad tails, but they are not long; and being spread out like a man's hand, they supply the place of oars when they are swimming. Though they have a thick coat of fur over all the rest of their bodies, their tails are quite bare and smooth, and slippery like seals. Hence in Germany and the northern regions, where beavers are plentiful, even the great, and men of religion, eat the tails during fasting seasons instead of fish, of the nature of which they partake in taste. - [Forester translation, 1863]

Aberdeen Bestiary [circa 1200 CE] (folio 11r): There is an animal called the beaver, which is extremely gentle; its testicles are highly suitable for medicine. Physiologus says of it that, when it knows that a hunter is pursuing it, it bites off its testicles and throws them in the hunter's face and, taking flight, escapes. But if, once again, another hunter is in pursuit, the beaver rears up and displays its sexual organs. When the hunter sees that it lacks testicles, he leaves it alone. Thus every man who heeds God's commandment and wishes to live chastely should cut off all his vices and shameless acts, and cast them from him into the face of the devil. Then the devil, seeing that the man has nothing belonging to him, retires in disorder. ... The name castor comes from castrando, 'castrate'.

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum Quadrupeds 4.14): Beavers, as Jacobus and Solinus say, are called castrando. Their testicles are called castorium and are suitable for medicine. On account of this, while pursued by the hunters, they castrate themselves with bites. When the hunter has collected the testicles, he lets the beast go. But if it is afterwards pursued by other hunters, in despair of escape it raises himself up, and shows to the hunter that its testicles have been cut off. The Poles say that this is false in those beavers who are with them, because the beaver's testicles do not protrude outside, but lie inside the belly. In the same way, it vomits bile, as Pliny says, useful for many medicines; and it believes itself to be persecuted for this reason. Its rennet calms the decaying disease. The trees by the river yield as iron [?]. This animal cannot live long unless it holds its tail in the water, because of course it has a tail like a fish. As the Experimentator says, its tail has the taste and appearance of a fish, whence it is eaten by Christians when fasting. A part of the tail can be used, but a part is prohibited for use; but the rest of its body is flesh. Now the tail of the beaver, as has been said, is like the tail of a fish, a cubit in length, and having much fat. Pliny: It therefore builds its house on the waters, making different rooms in it, so that it moves with the rising or falling of the waters. The beaver, in fact, feeds on the leaves and bark of bitter trees as the most delicious. This animal has a very powerful bite, and when it attacks something, it does not let go until it feels that what it is holding has cracked. As the Experimentator says, beavers live in herds, and they go to the woods in multitudes, and, having cut wood with their teeth, they carry it to their dens in a wonderful manner. For they throw one of them on the ground on its back with its feet raised as a vehicle, and artfully arrange cut wood between its legs, and in this way, dragging it by its tail, bring him down to it own home [something similar is said of the badger]. As the same Experimentator says, the beavers do not do such a wrong to the beavers who have been brought up among them, but to those who have come to them from foreign parts, and they reduce them to slavery under strong guard. But the opinion of others is that the beavers do this to those beavers who are worn out by old age and whose teeth are dulled by toil and are no longer able to cut wood for eating or building. Hunters recognize such enslaved beavers by the loss of the hairs on their backs, and moved with pity, they allow them to go unharmed. The same Experimentator above says a very surprising thing, but whether it is true, I do not know. they allow luter [otter] to live with them in the water, and this only by the grace of servitude at great cost, so that they move the water around with their tails in the season of cold, so that the water does not suddenly freeze through their tails, when they should be held by ice and captured. If they have no protectors for their tails, they worry about themselves and go down into the water only up to their knees, lest the water freeze in their middle despite their natural heat. They have two uses for cut wood: they eat the bark, and they make very artistic dwellings from the wood. The bark-eater sits raised on its hind legs and holds a stick with its front legs. When eating, they only peel off that part of the wood which they held between their feet; but what is beyond their feet they throw away and do not take care of. Its hind feet are like those of a goose, though larger and with claws, but its fore feet are like those of a dog; and in this nature is to be praised, which providentially provided the beasts with their hind feet, with which they could swim in the water like ducks and birds, and the forelegs, with which they could walk on the ground on all fours. When a beaver cuts down a tree, it runs away from the tree, in order to avoid the fall of the tree. If the tree is struck and does not fall, it strikes the tree with a blow from its teeth and continues to do this until it forces the tree to fall by repeated blows. The hunting of the beaver is done in this way: when the hunters come to the beaver's dwelling, a dog trained for this purpose is thrown into the water, which, reaching the opening of the dwelling, enters, and does not yield to the bites of the beaver, until that artificial dwelling of the beaver is broken by the hunters. This animal is after the manner of a Pontic dog, long, of course, and slender. It has very sharp teeth, two above and two below, which are the same, as the Liber Kyrannidarum says, and it has bony lips; and in this nature provided, that they should be able to cut down most trees. It has a delicate and noble skin, the blacker it is, the more valuable it is. The colors in the hairs are like the badger, but the hairs are fine and beautiful. Only the hair of this animal can be gilded in the skin, and the Eastern Muslims use them as ornaments for the head and weapons. Beaver fur warms and dries, and has a liquid used to reduce the spirit of those who suffer from spasm. And it is most useful for tremors of the limbs from a lack of nerves. The saginum of the testicles and groins of the beaver is of great value to the aforesaid. Wine boiled with beaver flesh, and the smell of the beaver itself kept close to a man suffering from paralysis, is thus an incomparable remedy. - [Badke translation/paraphrase]

Albertus Magnus [ca. 1200-1280 CE] (De animalibus, Book 22, 22): Castor has webbed feet like a goose to enhance its swimming and forefeet like a dog because it often travels on dry land. The word “castor” comes from “castrando” (castrating), not because the animal castrates itself as Isidore states, but because it is sought by hunters who castrate it for its musk. The story that, once disturbed by a hunter, the beaver will castrate itself with its own teeth, letting out the odiferous musk, and further, that if the castrated beaver is surprised by a hunter at a later date, it will rise up on its hind legs to show it has no musk, is absolutely false. The error of this fable has been repeatedly demonstrated by observers in our own country. Using its teeth, the beaver cuts down trees in predetermined lengths and constructs dwellings on the banks of streams. These dam-like structures are made accessible by entrances leading to the quarters it intends to inhabit. The beaver builds these lodges with two or three chambers on one level and another on an upper level, so it may ascend or descend according to the rise or fall in the depth of the water. In the course of erecting a dam, the beaver is believed to commandeer the services of an enslaved member of its species [a similar tale is told of the badger]. While the slave-beaver lies supine in the water, the wood-cutting beaver piles pieces of wood on thie slave’s abdomen, balancing them between its legs. The builder then grasps the slave’s tail and tows it through the water to the construction site, and in this manner gradually completes the house. The beaver’s pelt is ash-grey in color, tending toward black. At one time it was deemed a rare and costly fur but now its value has diminished. Its fur is thick and short-haired. The beaver eats fresh-water fish but also feeds on the barks of trees. The musk is located within its body and has a hot, dry quality which empowers it to strengthen nerves. Beaver musk works well in combating tremor and paralysis of the extremities, for it can isolate and dessicate the causative phlegmatic humor. The beaver has a very fat, broad tail covered with an almost scaly skin; it seems to delight in immersing its tail in the water. The tail is adapted for swimming, serving like the rudder of a ship. However, it is not true that it never removes its tail from the water, for it is known to retract the tail from the excessive cold of icy waters. Furthermore, the story that the beaver forces an otter to swim around and agitate the water near its tail so the water will not freeze and entrap its tail is patently false. But, because of its vicious bite, the beaver prevails over the otter and causes it to flee or kills it. With the exception of the flesh in its tail, beaver meat is barely palatable. Castoreum is a substance extracted from the beaver’s body, along with an equivalent amount of surrounding tissue fluid. After dessication the musk should have a fine consistency and the color of dark blood. If it is mottled and inclined to be black, it is poisonous and may cause death within twenty-four hours after ingestion; or it may exacerbate the illness for which it is taken, by adding serious complications. On the other hand, musk of good quality is hot and dry, and due to its subtle demoisturizing effect it is beneficial for the nerves and for paralytics, when it is heated and swallowed with the person’s own saliva. If a woman in labor is bled from the “saphena,” which is a vein of the liver in the forearm, and is made to drink two ounces of a mixture of catoreum and calamint in honey, she will deliver her baby and the afterbirth in a normal manner. The same treatment is used to promote a normal menstrual flow, though it is less effective if the vein is not bled. Finally, if the aforesaid mixture is consumed by men, it invigorates their testes. - [Scanlan]

Bartholomaeus Anglicus [13th century CE] (Liber de proprietatibus rerum, Book18.29): Castor is a wonderous beast, & liveth and goeth in land among foure footed beasts, and swimmeth under water, and dwelleth with Fish that swimme therin, and hath that name Castor, of Castrando, gelding, as Isidore sayeth, libro 12. for their gendering stones accorde to medicine, and because of the same stones they geld themselves when they be ware of the hunter, & bite off their gendering stones, as hée sayth. Cicero speaketh of him and sayth, that they raunsome themselves with that parte of the bodye, for the which they bée most pursued. And Juvenal sayth, that they geld themselves and loose theyr stones, for they desire to scape. And the Castor is called Fiber also, and is called a sea hound of Pontus. Huc usque Isidor[e]. Of Castoris Plinius speaketh, libro. 11. capitulo. 3. In Pontus hée sayth, is a manner kinde of beastes, that dwelleth now in lande and now in water, and maketh houses and dens arayed with wonderfull craft in the brinkes of rivers and of waters. For these beastes live together in flockes, and love beastes of the same kinde, and commeth together and cutteth rods and stickes with theyr téeth, and bringeth them hoame to theyr dens in a wonderfull wise, for they laye one of them on the grounde upryght in stéed of a slead or of a dray, with his legs and féete reared upward, and lay & loade the stickes and wood betwéene his legges and thighes, and draweth him home to their dens, and unlade and discarge him then [also said of the badger], and make them dwelling places ryght strong by great subtiltye of craft. In theyr houses bée two chambers or thrée distinguished, as it were thrée cellers, & they dwell in the over place when the water ariseth, & in the neather when the water is away, and each of them hath a certeine hole properly made in the celler, by the which hole he putteth out his taile in the water, for the taile is of fishy kind, he may not without water be long kept without corruption. And the beast is wonderfull and wonderfully shaped, for his taile onely is fish, and all the other deale of his bodye hath the kinde of a foure footed beast, and is shaped as a little hounde, and his hinder feete bée as it were the féete of an hound, & therwith he goeth principallye in the lande, and his two fore feete be as it were Goose féet, & therewith he swimmeth principallye in water. His skinne is full precious and hath téeth longer and shorter as a hound, and is not swift of mooving, for his legs be full short. And Castor hath two gendering stones that be greate in comparison to his little bodye, and we call these stones Castorea. And of these stones Plinius speaketh li. 32. ca. 3. and sayth, That the Castor biteth off his gendring stones that we call Castoria, and that least he be taken of hunters. And Sextinus, a most diligent sercher of medicine, denieth this: For he saith, that those gendring stones cleave so nigh & so fast to the ridge bone, yt they may not take them from the beast, but his life is taken also. Also Plat[o] sayth the same, and Dioscorides also: that that beast is not so wary nor so witty, that he could helpe himselfe in yt manner. And that is known all day in Castoris that be found in divers places. And so this that Isidore and Phisiologus tell of their gelding, shall not so be understood of the comon Castoris: But of some other beast yt be like Castores in gendering stones. And very Castorium & not feined, helpeth against the greatest evill of the bodye, as Plinius saith there, & namely if ye stones be of a Castor that is not too young nor too olde. And Castoria these stones be chosen in this manner: For they be double, & hang by one string, and coupled by one sinew, for such may not soone be feined. And many men take ye bladder of a beast, and fill it full of Castoris bloud, and put thereto a little of ye Castor to have smel, & a little pepper for to have sharp savour: and bindeth the necke of the bladder, for it should séeme a sinew, but it is impossible yt two bladders shoulde hang by one neck: and therefore ye Castorium is best, yt is double, & hangeth by one sinew. And ye Castorium is best that is meanly sharp in savour. For if it be too sharpe, & as it were earthie, then it is feined, & namely if it have not sinewes medled, as Diosc[orides] saith. And so good Castorium is meanely sharp of savour & glewie, without strong or salt savour: for with Sal aromaticum oft Castorium is feined, as Pli[ny] saith ther: The more feesh & new Castorium is, the better it is, & the more vertuous in medicine. And it is a token that it is not feined, when the stones have certeine skins yt cleave essentially thereto full of unctuous fatnesse, and may be kept seven yeares in greate vertue, & shall be put in medicine without the utter skin, and shal be weighed in due manner: and hath vertue to dissolve and temper, to consume & to wast, and to abate evill humours, and namely to comfort sinewy members: and so Castorium helpeth against many sicknesses & evills, for it accordeth to them yt have the falling evill, and helpeth against colde evills of the head, and doth awaye sodeine palsie of the tongue, and restoreth ye speech, if it be onely tempered in moysture under the tongue, & helpeth against universall & generall palsie of the body, if it be sod in wine with Rew and with Sage. And oft in meat & in drinke, exciteth, moveth, & comforteth the brain, and maketh to sneese: and therfore the Litargike man, yt hath the sléeping evill, is awaked therwith, & provoketh and causeth sléepe, if the head be anointed therwith, & Oleum Rosaceum, and helpeth against strong venim, & against the venim of scorpions, & of the serpent Cerastes, & of the Serpent Prester, as Plinius saith, libr. 8. cap. 3. Also his urine helpeth in all the foresaid things, as he saith, and exciteth menstruall bloud, and helpeth conception, and many other dooings, & his grease is most effectuall and vertuous in Ointments. - [Batman]