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 (Prado) other, and to their left on an altar is a small female figure, usually interpreted as a statue of a female divinity. She holds a sphere, variously interpreted as an egg or pomegranate. The group is 161 cm high and is now accepted as portraying Castor and Pollux. The lefthand figure was originally headless but was restored in the 17th century, the heyday of interpretive restorations, by Ippolito Buzzi, when the sculpture was in the collection of Cardinal Ludovico Ludovisi, using a Hadrianic-era (ca. 130) bust of Antinous of the Apollo-Antinous type from another statue. The identification of the figures