Angels are usually intended, in both Christian and Islamic art, to be beautiful, though several depictions go for more awesome or frightening attributes, notably in the depiction of the living creatures (which have bestial characteristics), ophanim (which are unanthropomorphic wheels) and cherubim (which have mosaic features); As a matter of theology, they are spiritual beings who do not eat or excrete and are genderless. Many angels in art may appear to the modern eye to be gendered as either male or female by their dress or actions, but until the 19th century, even the most female looking will normally lack breasts, and the figures should normally be considered as genderless. In 19th-century art, especially funerary art, this traditional convention is sometimes abandoned.