Bruno Bettelheim notes in "The Uses of Enchantment" that the 18th-century fairy tale "Beauty and the Beast" is a version of "Cupid and Psyche". Motifs from Apuleius occur in several fairy tales, including "Cinderella" and "Rumpelstiltskin", in versions collected by folklorists trained in the classical tradition, such as Charles Perrault and the Grimm brothers. In the Grimm version, Cinderella is given the task of sorting lentils and peas from ash, and is aided by birds just as ants help Psyche in the sorting of grain and legumes imposed on her by Venus. Like Cinderella, Psyche has two envious sisters who compete with her for the most desirable male. Cinderella's sisters mutilate their own feet to emulate her, while Psyche's are dashed to death on a rocky cliff. In Hans Christian Andersen's "The Little Mermaid", the Little Mermaid is given a dagger by her sisters, who, in an attempt to end all the suffering she endured and to let her become a mermaid again, attempt to persuade her to use it to slay the Prince while he is asleep with his new bride. She cannot bring herself to kill the Prince, however. Unlike Psyche, who becomes immortal, she doesn't receive his love in return, but she, nevertheless, ultimately earns the eternal soul she yearns for.