§ =21.= We now come to =the structure of the whole alliterative line=. The regular alliterative line or verse is made up of two hemistichs or sections. These two sections are separated from each other by a pause or break, but united by means of alliteration so that they form a rhythmical unity. Each hemistich must have two syllables which predominate over the rest in virtue of their logical and syntactical importance and have on this account a stronger stress. These stressed syllables, four in number for the whole line, count as the rhythmical accents of the verse. The force given to these accented syllables is more marked when they carry at the same time the alliteration, which happens at least once in each hemistich, frequently twice in the first and once in the second hemistich, and in a number of instances twice in both hemistichs. The effect of the emphasis given to these four words or syllables by the syntax, etymology, rhythm, and sometimes alliteration, is that the other words and syllables may for metrical purposes be looked upon as in comparison unaccented, even though they may have a main or secondary word-accent. In certain cases, in consequence of the particular structure of the hemistich, there is found a rhythmical secondary accent, generally coinciding with an etymological secondary accent, or with a monosyllable, or with the root-syllable of a disyllabic word. Sievers looks on these syllables as having in the rhythm of the verse the nature of a minor arsis (_Nebenhebung_); they rather belong to the class of syllables standing in thesis but with a slight degree of accent (_tieftonige Senkung_). The two sections of the alliterative line rarely exhibit a strict symmetry as to the number of the unaccented syllables and their position with regard to the accented syllables. In the great majority of cases their similarity consists merely in their having each two accented syllables, their divergence in other respects being very considerable. It is to be noted that certain combinations of accented and unaccented syllables occur with more frequency in one hemistich than in the other, or are even limited to one of the two hemistichs only. Besides the ordinary or normal alliterative line with four accents, there exists in Old English and in other West-Germanic poetry a variety of the alliterative line called the _lengthened line_ (_Schwellvers_ or _Streckvers_). In this line each hemistich has three accented syllables, the unaccented syllables standing in the same relation to the accented ones as they do in the normal two-beat hemistich.