An 1860 publication of Walt Whitman’s Leaves of Grass contains a table of contents, unlike some contemporaneous copies, and that particular table of contents depicts an image of a butterfly perched on a person’s finger.
The addition of a table of contents puts an emphasis on each poem as an individual work, rather than as just a part of the collection. This emphasis suggests that Whitman’s poems were well known and appreciated in their own right, not just along with “Song of Myself” and the other big name poems, or that the editor desired the poems to be more well known in their own context. Both interpretations have some merit.
The butterfly initially may seem like a trivial addition, meant only for decoration and nothing else. However, I don’t believe it to be some insubstantial doodle added in the margin to fill up blank space on the page. Leaves of Grass is a collection that is focused generally on nature poems and nature imagery in poetry. A butterfly, one of the most iconic images of the beauty of nature, is a great way to set the stage at the very beginning of the book, before the verse even begins. It prepares the reader for a journey through Whitman and his poetry by subtly creating the atmosphere of nature and natural scenes interacting with the world people live in.