Domestic breeding efforts have resulted in numerous varieties of rabbits that do not occur in nature. The Castor Rex, for instance, was developed in the early 1900s as a type of rabbit that has a coat that contains no guard hairs. Perhaps better known, however, is the Angora rabbit, which exhibits very fine hair with a soft texture and an exceptional luster. The hair of Angora rabbits is also unusually long because of the presence of a recessive gene that prolongs the active phase of the hair growth cycle. Of significant economic value, the hair of Angora rabbits is generally utilized to fabricate items such as luxurious fur coats and wraps.