North American beaver large, webbed hind feet. The unwebbed front paws are smaller, with claws. The eyes are covered by a nictitating membrane which allows the beaver to see under water. The nostrils and ears are sealed while submerged. A thick layer of fat under its skin insulates the beaver from its coldwater environment. The beaver's fur consists of long, coarse outer hairs and short, fine inner hairs (see Double coat). The fur has a range of colors, but usually is dark brown. Scent glands near the genitals secrete an oily substance known as castoreum, which the beaver uses to waterproof its fur.
Castor and Pollux her. In revenge they abducted Theseus's mother Aethra and took her to Sparta while setting his rival, Menestheus, on the throne of Athens. Aethra was then forced to become Helen's slave. She was ultimately returned to her home by her grandsons Demophon and Acamas after the fall of Troy. Castor and Pollux aspired to marry the Leucippides ("daughters of the white horse"), Phoebe and Hilaeira, whose father was a brother of Leucippus ("white horse"). Both women were already betrothed to cousins of the Dioscuri, the twin brothers Lynceus and Idas of Thebes, sons of Tyndareus's brother Aphareus. Castor and Pollux