It hath been propagated by Emblems: and some have been so bad Grammarians as to be deceived by the Name, deriving Castor à castrando, whereas the proper Latine word is Fiber, and Castor but borrowed from the Greek, so called quasi γάστωρ, that is, Animal ventricosum, from his swaggy and prominent belly.
Herein therefore to speak compendiously, we first presume to affirm that from strict enquiry, we cannot maintain the evulsion or biting off any parts, and this is declarable from the best and most professed Writers: for though some have made use hereof in a Moral or Tropical way, yet have the professed Discoursers by silence deserted, or by experience rejected this assertion. Thus was it in ancient times discovered, and experimentally refuted by one Sestius a Physitian, as it stands related by Pliny; by Dioscorides, who plainly affirms that this tradition is false; by the discoveries of Modern Authors, who have expressly discoursed hereon, as Aldrovandus, Mathiolus, Gesnerus, Bellonius; by Olaus Magnus, Peter Martyr, and others, who have described the manner of their Venations in America; they generally omitting this way of their escape, and have delivered several other, by which they are daily taken.
The original of the conceit was probably Hieroglyphical, which after became Mythological unto the Greeks, and so set down by Æsop; and by process of tradition, stole into a total verity, which was but partially true, that is in its covert sense and Morality. Now why they placed this invention upon the Bever (beside the Medicable and Merchantable commodity of Castoreum, or parts conceived to be bitten away) might be the sagacity and wisdom of that Animal, which from the works it performs, and especially its Artifice in building, is very strange, and surely not to be matched by any other. Omitted by Plutarch, De solertia Animalium, but might have much advantaged the drift of that Discourse.
If therefore any affirm a wise man should demean himself like the Bever, who to escape with his life, contemneth the loss of his genitals, that is in case of extremity, not strictly to endeavour the preservation of all, but to sit down in the enjoyment of the greater good, though with the detriment and hazard of the lesser; we may hereby apprehend a real and useful Truth. In this latitude of belief, we are content to receive the Fable of Hippomanes, who redeemed his life with the loss of a Golden Ball; and whether true or false, we reject not the Tragœdy of Absyrtus, and the dispersion of his Members by Medea, to perplex the pursuit of her Father. But if any shall positively affirm this act, and cannot believe the Moral, unless he also credit the Fable; he is surely greedy of delusion, and will hardly avoid deception in theories of this Nature. The Error therefore and Alogy in this opinion, is worse then in the last; that is, not to receive Figures for Realities, but expect a verity in Apologues; and believe, as serious affirmations, confessed and studied Fables.
Again, If this were true, and that the Bever in chase makes some divulsion of parts, as that which we call Castoreum; yet are not the same to be termed Testicles or Stones; for these Cods or Follicles are found in both Sexes, though somewhat more protuberant in the Male. There is hereto no derivation of the seminal parts, nor any passage from hence, unto the Vessels of Ejaculation: some perforations onely in the part it self, through which the humour included doth exudate: as may be observed in such as are fresh, and not much dried with age. And lastly, The Testicles properly so called, are of a lesser magnitude, and seated inwardly upon the loins: and therefore it were not only a fruitless attempt, but impossible act, to Eunuchate or castrate themselves: and might be an hazardous practice of Art, if at all attempted by others.
Now all this is confirmed from the experimental Testimony of five very memorable Authors: Bellonius, Gesnerus, Amatus, Rondeletius, and Mathiolus: who receiving the hint hereof from Rondeletius in the Anatomy of two Bevers, did find all true that had been delivered by him, whose words are these in his learned Book De Piscibus: Fibri in inguinibus geminos tumores habent, utrinque vnicum, ovi Auscrini magnitudine, inter hos est mentula in maribus, in fæminis pudendum, hi tumores testes non sunt, sed folliculi membrana contecti, in quorum medio sunguli sunt meatus è quibus exudat liquor pinguis et cerosus, quem ipse Castor sæpe admoto ore lambit et exugit, postea veluti oleo, corporis partes oblinit: Hos tumores testes non esse hinc maxime colligitur, quod ab illus nulla est ad mentulam via neque ductus quo humor in mentulæ meatum derivitur, et foras emittatur; præterea quod testes intus reperiuntur, eosdem tumores Moscho animali inesse puto, è quibus odoratum illud plus emanat. Then which words there can be no plainer, nor more evidently discovering the impropriety of this appellation. That which is included in the cod or visible bag about the groin, being not the Testicle, or any spermatical part; but rather a collection of some superfluous matter deflowing from the body, especially the parts of nutrition as unto their proper emunctories; and as it doth in Musk and Civet Cats, though in a different and offensive odour; proceeding partly from its food, that being especially Fish; whereof this humour may be a garous excretion and olidous separation.
Most therefore of the Moderns before Rondeletius, and all the Ancients excepting Sestius, have misunderstood this part, conceiving Castoreum the Testicles of the Bever; as Dioscorides, Galen, Ægineta, Ætius, and others have pleased to name it. The Egyptians also failed in the ground of their Hieroglyphick, when they expressed the punishment of Adultery by the Bever depriving himself of his testicles, which was amongst them the penalty of such incontinency. Nor is Ætius perhaps, too strictly to be observed, when he prescribeth the stones of the Otter, or River-dog, as succedaneous unto Castoreum. But most inexcusable of all is Pliny, who having before him in one place the experiment of Sestius against it, sets down in another, that the Bevers of Pontus bite off their testicles: and in the same place affirmeth the like of the Hyena. Which was indeed well joined with the Bever, as having also a bag in those parts; if thereby we understand the Hyena odorata , or Civet Cat, as is delivered and graphically described by Castellus. Castellus de Hyena odorifera.
Now the ground of this mistake might be the resemblance and situation of these tumours about those parts, wherein we observe the testicles in other animals. Which notwithstanding is no well founded illation, for the testicles are defined by their office, and not determined by place or situation; they having one office in all, but different seats in many. For beside that, no Serpent, or Fishes oviparous, that neither biped nor quadruped oviparous have testicles exteriourly, or prominent in the groin; some also that are viviparous contain these parts within, as beside this Animal, the Elephant and the Hedg-hog.
If any therefore shall term these testicles, intending metaphorically, and in no strict acception; his language is tolerable, and offends our ears no more then the Tropical names of Plants: when we read in Herbals, of Dogs, Fox, and Goat-stones. But if he insisteth thereon, and maintaineth a propriety in this language: our discourse hath overthrown his assertion, nor will Logic permit his illation; that is, from things alike, to conclude a thing the same; and from an accidental convenience, that is a similitude in place or figure, to infer a specifical congruity or substantial concurrence in Nature.