In literary poetry, however, the tripartite stanzas are commoner than the bipartite unequal-membered stanzas just noticed; they are as much in favour as the bipartite, equal-membered stanzas are in popular poetry. In Provençal and Northern French poetry the principle of a triple partition in the structure of stanzas was developed very early. Stanzas on these models were very soon imported into Middle English poetry. § =226.= The =tripartite= stanzas generally (apart from Modern English forms) consist of two equal parts and one unequal part, which admit of being arranged in different ways. They have accordingly different names. If the two equal parts precede they are called _pedes_, both together the _opening_ (in German _Aufgesang_ ='upsong'); the unequal part that concludes the stanza is called the _conclusion_ or the _veer_, _tail_, or _cauda_ (in German _Abgesang_ ='downsong'). If the unequal part precedes it is called _frons_ (='forehead'); the two equal parts that form the end of the stanza are called _versus_ ('turns,' in German _Wenden_). The former arrangement, however, is by far the more frequent. There are various ways of separating the first from the last part of the stanza: (a) by a pause, which, as a rule, in Romanic as well as in Middle English poetry occurs between the two chief parts; (b) by a difference in their structure (whether in rhyme-arrangement only, or both in regard to the kinds and the number of verses). But even then the two chief parts are generally separated by a pause. We thus obtain three kinds of tripartite stanzas: 1. Stanzas in which the first and the last part differ in _versification_; the lines of the last part may either be longer or shorter than those of the 'pedes'. Difference in rhythmical structure as well as in length of line is in Middle English poetry confined to the _bob-wheel_ stanzas, and is not otherwise common except in Modern English poetry. 2. Stanzas in which the parts differ in _number of verses_. The number may be either greater or smaller in the last part than in the two 'pedes', which, of course, involves at the same time a difference in the order of the rhymes. Change of length, however, and change of versification in the last part in comparison with the half of the first part are generally combined. 3. Stanzas in which the parts agree in versification but _differ in the arrangement of the rhymes_; the number of verses in the _cauda_ being either the same as that of one of the _pedes_, or (as commonly the case) different from it. In all these cases the first and the last part of the stanza may have quite different rhymes, or they may, in stanzas of more artistic construction, have one or several rhymes in common. If the _frons_ precedes the _versus_, the same distinctions, of course, are possible between the two chief parts.