That is to say, the third and seventh elements, which were always short in Greek, were "anceps" (either long or short) in Latin; in fact they are long 60% of the time, while the Greek "anceps" syllables (the first, fifth, and ninth elements) are long in 80-90% of lines. As in the Greek trimeter, any long or "anceps" syllable except the last could be replaced with a double short syllable (u u). As in Greek, there was usually (though not always) a "caesura" (word-break) after the fifth element.