The beaver is a four-footed animal who lives in pools. A beaver’s genitals serve, it is said, to cure certain ailments. So when the beaver is spotted and pursued to be mutilated – since he knows why he is being hunted – he will run for a certain distance, and he will use the speed of his feet to remain intact. But when he sees himself about to be caught, he will bite off his own parts, throw them, and thus save his own life.
Among men also, those are wise who, if attacked for their money, will sacrifice it rather than lose their lives.
NOTE: It was believed in antiquity that the valued secretion castorea was obtained from the beaver’s scrotum, hence ‘biting off his own parts’ in the fable. We now know that the secretion is found in two separate sacs and not actually in the scrotum. The name of the beaver in Greek is castor , the same as the twin-god, and also the same as one name given to the crocus, source of saffron. There is little doubt that a complex of mythological meanings is involved here. A cognate word is found in Sanskrit, kasturi( kā ) orkastūri( kā ), meaning both ‘musk deer’ and ‘musk’, and thus referring to the secretions of the musk deer rather than the beaver. Since these word forms are isolated in both Greek and Sanskrit, they are probably loan-words originating from a very early trade in aromatic animal secretions supplied by Indo-European tribes to the Middle East. The etymology of the words is probably from the Egyptian qas , orqes. That word means ‘efflux’ and, because it also means ‘vomit’, the Egyptians probably applied the same word to ambergris, which is whale vomit, and the substances castorea and musk. The word also means ‘to prepare a mummy for burial’, so we suspect that the uses of these substances were for mummification. The same Egyptian word means ‘fetters that bind’ (i.e. also mummy-wrappings), and the Greek god Castor was reputed to be the inventor of manacles, thus probably carrying over an Egyptian pun at an early date. An apparent cognate with the Egyptian is found in Akkadian, where kasitu means ‘being bound or fettered’, from kasu , ‘to bind’. Curiously, the Akkadian kāsistu, with the long initial vowel, refers to a rodent, from kasasu, ‘to gnaw’ or ‘gnaw through’, which is, of course, so characteristic of the beaver. Aristotle, our chief Greek zoological authority, was uneasy about the word castōr as applied to the beaver. He actually speaks of the ‘so-called castōr” kaloumenos castōr ) in the History of Animals, and proceeds to call the beaver by the name which he clearly regarded as its true name, latax, and which he describes as cutting down the riverside aspens or poplars with its teeth. Aristotle seems to have suspected that castōr was a synonym for the beaver arising from some unusual source, which we can see was probably by association from the name for its aromatic secretion being applied to the animal itself