NOTE: Most of the common verses originally consisted of two series (hemistichs), but the joint between them is often obscured. It is marked in Iambic and Trochaic Tetrameter by the Diaeresis, in Dactylic Hexameter by the Caesura.
a. A verse lacking a syllable at the end is called Catalectic, that is, having a pause to fill the measure ; when the end syllable is not lacking, the verse is called Acatalectic, and has no such pause.
b. A final syllable, regularly short, is sometimes lengthened before a pause:[This usage is comparatively rare, most cases where it appears to be found being caused by the retention of an originally long quantity.] it is then said to be long by Diastole: -