Zuleika
Zuleika herself is a sort of symbol, one with many different facets. She is a symbol of the dangerous aspect of beauty, as beauty can be perilous when used improperly. Zuleika, by not discouraging the mass suicide of the Oxford students, clearly used her beauty improperly and did not steward her gift well, causing pain and death rather than pleasure. She also symbolizes the stereotypical selfish, beautiful girl, despite any claims she might make to the contrary. These two symbolisms are evident throughout the novel, and they accord with Beerbohm's nature as a caricaturist.
The Duke of Dorset
The other main character of the novel, the Duke of Dorset, is another sort of symbolic caricature. The Duke represents the type of serious young university student who sees himself as elite and important on the basis of his talents and self-deportment. He is, however, a caricature as well, as he takes his seriousness to an extreme, believing an ill omen to be a harbinger of his death and subsequently drowning himself in the river because he believes it's the right thing to do. This gravitas is clearly exaggerated, therefore making the Duke a sort of symbolic representation of a larger, more prevalent underlying psychology.
The Pearls
One of the oddly supernatural elements of the novel doubles as an obvious symbol: the pearls worn by both Zuleika and the Duke. Near the beginning of the novel, the Duke has dinner with Zuleika and her grandfather, in the course of which Zuleika and the Duke fall in love with each other. The duke realizes that two of the white pearls in his shirt-front has been transformed into pink and black, the colors of love. The next day, when Zuleika visits, the Duke notices that her pearl earrings, previously pink and black, are now both white. The symbolism in this transformation confirms the Duke's suspicions; Zuleika has given him her heart, being completely in love. When Zuleika realizes her mistakes about the Duke, however, both sets of pearls switch back to their original colors, representing Zuleika's change of heart.
Zuleika's Occupation
Zuleika is a prestidigitator (sleight-of-hand magician), and although she's not very talented in the field, she becomes quite successful as a result of her allure for her (typically male) audiences. This particular occupation is symbolic of Zuleika's true nature: despite her beautiful appearance, she is actually a selfish and thoughtless person, as evidenced by her allowance of the undergraduates' mass suicide, as well as her request that the Duke shout her name as he jumps into the river to drown himself. On the surface, she seems lovely, but this beauty is simply an illusion.
The River
The river in which the Duke drowns himself is symbolic of defeatism. Having decreed his own death as a result of a mysterious omen, the Duke quickly selects the river, a place of beauty yet constantly, overwhelming change, as his final resting place, representing his complete and utter resignation to his fate. As the rest of the young men of Oxford follow suit, drowning themselves in this river, it parallels the river's torrential crescendo during the fateful rainstorm.
