The _Parlement of Foules_ shows development thus in detail. The total composition, the movement of the whole, is still to seek. Here again are conventional allegory, this time mainly from Alain de Lille,[28] rehearsal from the medieval treasury, dream-vision, decorative description, without any narrative progress. But the allegory is vivified as in _Piers Plowman_. The classes are differentiated by the lively speech of their representatives. The interaction, though elementary, is more than mere _débat_. There is even approach to individual character in distinguishing the second tercel from the first. In these modifications there is promise[29] of a still more characteristic achievement, the interludes of the _Canterbury Tales_. 2. Poetic Innovation in _Troilus and Criseyde_ The narrative stanza of _Troilus and Criseyde_ is a technical triumph. Even the rich harmonies of The _Faerie Queene_ hardly dispute its eminence; for they are adjusted rather to description. Chaucer’s stanza is narrative in sure and fluent onwardness. It so furthers the movement of the story as rarely to invite separate attention, so deftly merges with the other means of narrative suggestion that its values transpire not from quoting this stanza or that, but from reading on and on. No other verse narrative is more satisfying to read aloud. The subtle harmonies of _Pearl_ are adapted to lyric reflection. The easy movement of _Childe Harold_ pauses again and again on picturesqueness. A fairer comparison is Byron’s triumph of fluency, _Don Juan_. Those stanzas have the same achievement of onwardness where Byron gives himself to the story. Chaucer’s story, deeper, more consistent, more progressive, is always his main concern. His distinction is in making his stanza constantly serve this.