In his successive revisions of the Hymn in the Nativity, Crashaw shows a growing sense of form, and the final version, posthumously published in 1652, has a conceptual unity that raises it to a level of poetry considerably above that of the 1646 version. He achieved this by substituting structural symbols for mere sense images, by emending a few lines, by dropping one stanza, and by adding two very important new stanzas that make the structural pattern of the poem much clearer. These changes had a considerable effect on the rest of the poem because they placed it in a new context. Miss Wallerstein, who notes the “steady pruning of the purely sensuous elements,” and who calls these additional stanzas “the great stanzas which transmute the whole,” describes the final version of the poem as one of Crashaw's “few perfectly realized poems.” A comparison of the text of 1646 with the texts of 1648 and 1652 enables us to study the poet in the process of this realization and to see how large a part clarification of structure played in it.