Its fifth appearance was in "Sibylline Leaves," 1817, again with some important changes, and the addition of the Latin motto and the marginal gloss.

In the "Poetical Works," 1828, and again in the "Poetical Works," 1829, the poem appeared in its final form as we now have it,--differing very little from the form it had in "Sibylline Leaves." One or two significant minor changes will be mentioned in the notes.
Coleridge's own account of the genesis of the poem, given in the _Biographia Literaria_ nearly twenty years later, is interesting.
"During the first year that Mr.Wordsworth and I were neighbours, our conversations turned frequently on the two cardinal points of poetry, the power of exciting the sympathy of the reader by a faithful adherence to the truth of nature, and the power of giving the interest of novelty by the modifying colours of imagination.

The sudden charm, which accidents of light and shade, which moonlight or sunset, diffused over a known and familiar landscape, appeared to represent the practicability of combining both.

These are the poetry of nature.

The thought suggested itself (to which of us I do not recollect) that a series of poems might be composed of two sorts.