CODEX (Lat. a board, either waxed for writing or the cover of a book), a bound book either of single leaves or quires: originally the form of a notebook or account book, it appears to have been used for Christian lit. from an early date and perhaps for the originals of some NT books. Probably first used in the W, it was already predominating over the scroll as the form of the Christian Scriptures even in Egypt by the mid-3rd cent.
C. C. MacCown, Codex and Roll in the NT, HTR 34 (1941), 219-250; C. H. Roberts, The Christian Book and the Greek Papyri, JTS 46 (1945), 155-168; F. G. Kenyon, Books and Readers in Ancient Greece and Rome, 2nd. ed. (1951).