Castoreum Castoreum Castoreum is a yellowish exudate from the castor sacs of the mature North American beaver ("Castor canadensis") and the European beaver ("Castor fiber"). Beavers use castoreum in combination with urine to scent mark their territory. Both beaver sexes have a pair of castor sacs and a pair of anal glands, located in two cavities under the skin between the pelvis and the base of the tail. The castor sacs are not true glands (endocrine or exocrine) on a cellular level, hence references to these structures as preputial glands, castor glands, or scent glands are misnomers. It is used as
Castor and Pollux Castor (Alpha Geminorum) and Pollux (Beta Geminorum). As emblems of immortality and death, the Dioscuri, like Heracles, were said to have been initiated into the Eleusinian mysteries. Castor and Pollux are consistently associated with horses in art and literature. They are widely depicted as helmeted horsemen carrying spears. The Pseudo-Oppian manuscript depicts the brothers hunting, both on horseback and on foot. On votive reliefs they are depicted with a variety of symbols representing the concept of twinhood, such as the "dokana" (δόκανα – two upright pieces of wood connected by two cross-beams), a pair of amphorae, a pair of shields,