The _Pervigilium Veneris_ is written in the trochaic septenarian verse which had been freely used by the earliest Roman poets, but had since almost dropped out of literary use. With the revival of the trochaic movement the long divorce between metrical stress and spoken accent begins to break down. The metre is indeed accurate, and even rigorous, in its quantitative structure; but instead of the prose and verse stresses regularly clashing as they do in the hexameter or elegiac, they tend broadly towards coinciding, and do entirely coincide in one-third of the lines of the poem. We are on the very verge of the accentual Latin poetry of the Middle Ages, and the affinity is made closer by the free use of initial and terminal assonances, and even of occasional rhyme. The use of stanzas with a recurring refrain was not unexampled; Virgil, following Theocritus and Catullus, had employed the device with singular beauty in the eighth _Eclogue_; but this is the first known instance of the refrain being added to a poem in stanzas of a fixed and equal length;[11] it is more than halfway towards the structure of an eleventh-century Provençal _alba_. The keen additional pleasure given by rhyme was easily felt in a language where accidental rhymes come so often as they do in Latin, but the rhyme here, so far as there is any, is rather incidental to the way in which the language is used, with its silvery chimes and recurrences, than sought out for its own sake; there is more of actual rhyming in some of the prose of Apuleius. The refrain itself- _Cras amet qui nunquam amavit, quique amavit cras amet--_ has its internal recurrence, the folding back of the musical phrase upon itself; and as it comes over and over again it seems to set the whole poem swaying to its own music. In one of the most remarkable of his lyrics (like this poem, a song of spring), Tennyson has come very near, as near perhaps as it is possible to do in words, towards explaining the actual process through which poetry comes into existence: _The fairy fancies range, and lightly stirr'd, Ring little bells of change from word to word_. In the _Pervigilium Veneris_ with its elaborate simplicity-- partly a conscious literary artifice, partly a real reversion to the childhood of poetical form--this process is, as it were, laid bare before our eyes; the ringing phrases turn and return, and expand and interlace and fold in, as though set in motion by a strain of music. _Cras amet qui nunquam amavit, quique amavit cras amet; Ver novum, ver iam canorum, ver renatus orbis est; Vere concordant amores, vere nubunt alites Et nemus comam resolvit de maritis imbribus: Cras amet qui nunquam amavit, quique amavit cras amet--_