It is common to all these trochaic metres that their structure, especially that of the longer ones, is (except for the varying caesura) very regular, and that they have only very few rhythmical licences, chiefly slight slurring.
CHAPTER XIV
IAMBIC-ANAPAESTIC AND TROCHAIC-DACTYLIC METRES
§ 189. The iambic-anapaestic rhythm has been touched on before in connexion with the four-stressed verse (cf. § [72]) which was developed from the alliterative long line, and which at the end of the Middle English and in the beginning of the Modern English period, under the growing influence of the even-beat metres, had assumed more or less regular iambic-anapaestic character.
When during the same period a definitive separation of the rising and falling rhythms took place, the even-measured rhythm of this four-stressed modern metre became more conspicuous and was made up frequently, although not always, of a regular series of iambic-anapaestic measures. It was thus differentiated still more distinctly from the uneven-beat Old and Middle English long line, the character of which mainly rested on the four well-marked beats only. It deserves notice further that it was not until the Modern English period that the rest of the iambic-anapaestic and trochaic-dactylic metres (the eight-, seven-, six-, five-, four-, three-, and two-foot verses) were imitated from the then common corresponding iambic rhythms.
In the sixteenth century Puttenham quotes four-foot dactylics, and in his time the dactylic hexameter had already been imitated in English. But most of the other trisyllabic rising and falling metres, except the Septenary, occur first in English poetry at the end of the eighteenth and during the course of the nineteenth century.
It must also be noted that in many cases, especially in the eight-, four-, and two-foot verses of this kind (i.e. in those metres that are connected with the old four-stressed verse), the rising and falling rhythms are not strictly separated, but frequently intermingle and even supplement one another.