We may distinguish between two kinds of inversion of rhythm, viz. (i) _natural_ inversion, and (2) _rhetorical_ inversion. The former is caused by word-accent, the latter by the rhetorical accent, as illustrated by the last examples. The second kind differs very clearly from level stress, as the word in question or the first syllable of it (see the second line of the following quotation) is to be uttered with an unusually strong emphasis, e.g.: Síck, or _in héalth, | in évil fáme or góod._ Surrey, p. 17. Lústy _of scháip,_ lýght of _delíveránce_. Dunbar, Thriss. and Rois 95. In the second example inversion of rhythm occurs (as it often does) twice over, viz. at the beginning of the verse and after the caesura. Not unfrequently also two inversions of rhythm follow immediately upon one another, e.g.: Wórldly gládnes | _is mélled wíth affráy_. Lydgate, Min. Poems, xxii, line 11. Réigned óver | _so mány péoples and réalms._ Surrey, p. 135. Such verses, however, may also be looked upon as instances of the omission of anacrusis combined with epic caesura. This would be the only admissible explanation in verses the first accented word of which is a word which usually does not bear an accent or is not accented rhetorically, e.g.: _Óf the wórdes | that Týdeús had sáid._ Lydgate, St. of Thebes, line 1082. _Tó have líved | áfter the cíty táken._ Surrey, p. 139. But in a line with an emphasized first word inversion of rhythm is the more probable explanation: e.g. _Nát astónned, | nor ín his hérte afférde._ Lydgate, St. of Thebes, line 1069. _Gód, that séndeth, | withdráweth wínter shárp._ Surrey, p. 58. § =89. Disyllabic or polysyllabic thesis.= Another important deviation from the regular iambic rhythm, which is clearly to be distinguished from the double thesis caused by inversion of rhythm, consists in the use of two or sometimes even more unaccented syllables instead of one to form a regular thesis of a verse. This irregularity, which is almost as common in Modern English as it is in Early English poetry, may occur in any part of the verse. If it occurs in the first foot, it may be called disyllabic or polysyllabic anacrusis, as in the following examples: _Gif we clépieþ híne féder þénne._ Pater Noster, 19. _Se þe múchel vólȝeð hís iwíl, | him sélue hé biswíkeð._ Moral Ode, 15. _To purvéie þám a skúlkyng, | on þe Énglish éft to ríde._ Rob. Mannyng, Chron. p. 3, l. 8. _With a thrédbare cópe, | as ís a póure scolér._ Chaucer, Prol. 260. _And why thís is a revelációun._ Chaucer, H. of Fame, l. 8.