In MS 286 [i.e., the Gospel Book of Saint Augustine] the words are laid out in the pattern which is called ‘per cola et commata’, meaning something like ‘by clauses and pauses’, in which the first line of each sentence fills the width of the column and any second or subsequent lines are written in shorter length. The format was almost certainly that of Jerome’s original manuscript of the Vulgate and it is characteristic of the very earliest copies. Each unit is probably what a person would read and speak aloud in a single breath. Thus Matthew opens, ‘The book of the generation of Jesus Christ, son of David, son of Abraham’, pause, take a breath, glance down silently at the next phrase, ‘Abraham begat Isaac’, another intake of breath, look back again at the text, ‘And Isaac begat Jacob, [and] Jacob begat Judah and his brothers’, breathe again, and so on. Winston Churchill typed his great speeches like this, so that they could be read at a glance and his famous oratorical pauses were graphically preordained in the layout of his script. It is an arrangement prepared primarily for reading aloud, which itself tells us something about the Gospel Book of Saint Augustine, which comes from a time of oral culture when most of the audience for the Scriptures was illiterate.

Christopher de Hamel, Meetings with Remarkable Manuscripts: Twelve Journeys into the Medieval World, 21-22.