It would be out of place here to enter into the question of prehistoric forms of Teutonic poetry. It will be enough to say that in Sievers's opinion a primitive form of this poetry was composed in strophes or stanzas, intended to be sung and not merely to be recited; that at a very early period this sung strophic poetry gave way to a recited stichic form suitable to epic narrations; and that his five-type forms are the result of this development. As all the attempts to show that certain Old English poems were originally composed in strophic form[53] have proved failures, we may confidently assent to Sievers's conclusion that the alliterative lines (as a rule) followed one upon another in unbroken succession, and that in historic times they were not composed in even and symmetrical measures (_taktierend_), and were not meant to be sung to fixed tunes. The impossibility of assuming such symmetrical measures for the Old English poetry is evident from the mere fact that the end of the line does not as a rule coincide with the end of the sentence, as would certainly be the case had the lines been arranged in staves or stanzas meant for singing. The structure of the alliterative line obeys only the requirements of free recitation and is built up of two hemistichs which have a rhythmical likeness to one another resulting from the presence in each of two accented syllables, but which need not have, and as a matter of fact very rarely have, complete identity of rhythm, because the number and situation of the unaccented syllables may vary greatly in the two sections. § =18. Accentuation of Old English.= As the versification of Old English is based on the natural accentuation of the language, it will be necessary to state the laws of this accentuation before giving an account of the five types to which the structure of the hemistich has been reduced. In simple polysyllables the chief or primary accent, in this work marked by an acute (´), is as a rule on the root-syllable, and the inflexional and other elements of the word have a less marked accent varying from a secondary accent, here marked by a grave (`), to the weakest grade of accent, which is generally left unmarked: thus _wúldor_, _héofon_, _wī́tig_, _wúnode_, _ǽðelingas_, &c. In the alliterative line, as a general rule, only syllables with the chief accent carry either the alliterating sounds or the four rhythmical accents of the verse. All other syllables, even those with secondary accent, count ordinarily as the 'theses' (_Senkungen_) of the verse[54]: _síndon þā =b=éarwas =b=lḗdum gehóngene =w=lítigum =w=ǽstmum: þǣr nō wániað ṓ =h=ā́lge under =h=éofonum =h=óltes frǽtwe_. Phoenix 71-73.