The quarto edition of 1596 was also published by Ponsonby, and contains Books I-VI, variously bound into one or two volumes. Books I-III were completely reset, apparently not from the MS. but from a copy of 1590 heavily annotated by the author. Some, but not all, of the corrections listed in the Faults Escaped were incorporated in 1596. The end of Book III was changed, continuing rather than ending the story of Scudamour and Amoret. Spenser also added a new stanza at the beginning of Book I, Canto xi, rewrote some single lines, and made sundry adjustments to others. This process continued even as pages passed through the press, so that there is variation from copy to copy, made more complex by the mixing of sheets from different printings during binding. No single copy of 1596 can therefore be said to be definitive. 1596 does, however, have the advantage of Spenser's personal supervision, and for this reason it is chosen as the core of modern composite texts. The third edition of _The Faerie Queene_ was published by Mathew Lownes in 1609, ten years after Spenser's death. It is a folio edition, and contains not only Books I-VI but also two cantos "which, both for Forme and Matter, appeare to be parcell of some following Booke of the Faerie Queene, vnder the Legend of Constancie". This fragment comprises what are now called the "Mutability Cantos". The edition of 1609 is fundamentally a reprint of 1596. There is reason to suspect that its editor was guided, at least in part, by some authorial source which has now been lost: an annotated copy of 1596, perhaps; or material found among the assorted papers of the Mutability Cantos. 1609 is a conscientious edition which often achieves a higher degree of consistency and intelligibility than 1596 itself, although it is plain that a more modern hand than Spenser's is responsible for many of its emendations: the punctuation, for example, though often more logical, is blander than that of the editions produced in Spenser's lifetime. Furthermore, the editor of 1609 virtually ignores 1590, even though knowledge of that text is often essential for filling in the gaps left by errors in 1596. The editions of 1611 onwards throw little light on problems raised by the three former editions. A modern editor, then, must go to three different sources in order to assemble a text which tries to do justice to Spenser's original intention. The copy-text for this edition is the facsimile published in 1976 by Scolar Press (see Bibliography). THE FORM OF THE POEM The basic unit of the poem is a verse or _stanza_ made up of nine lines. This "Spenserian stanza", much imitated (for example, by Byron), is Spenser's own invention. Typically, it consists of eight pentameters and a final alexandrine. Lines are sometimes short or long, on occasion perhaps through typographical error (see for example II iii 26.9), but at other times for deliberate effect (e.g. III iv 39.7, IV i 3).