In Canto One of his poem John Shade (the poet in VN’s novel Pale Fire, 1962) compares our world to a cage and says that “we are most artistically caged:”
My picture book was at an early age
The painted parchment papering our cage:
Mauve rings around the moon; blood-orange sun;
Twinned Iris; and that rare phenomenon
The iridule - when, beautiful and strange,