Metaphor in The Importance of Being Earnest
Miss Prism gently mocks the Chasuble, mirroring the structure of his earlier statement ("my metaphor was drawn from bees") and building on its sexual overtones by referring to women as either ripe or green (unripe). This metaphor suggests that a young woman like Cecily, for instance, can't always be trusted, but an older, more mature woman like Miss Prism certainly can be (and wants to be).
Wilde doesn't belabor the point, but by placing the manuscript in the basinette he signifies to the reader that this is Miss Prism's child, and that this work that she has labored over in her off hours has become more important to her than a real-life baby, whom she thoughtlessly leaves in a train station. This may be how Wilde himself feels about his writing: that it is like his child, and that he cares for it as if it were his flesh and blood. Metaphorically speaking, it probably is.