Although the quantitative theory of modern verse has been pretty generally abandoned, it cannot be said that the ordinary view which regards the foot as the unit of verse and its rhythm as determined by a regular distribution of accented and unaccented syllables, is in a much better case. For in the first place, by accent is usually meant word-accent; but monosyllabic words have no word-accent; hence, in a succession of such syllables, the accent must be determined by some other factor; and, granting this, there is the further fact to be reckoned with, that poetic accent is relative--the supposedly unaccented syllable is often very highly accented, more highly in fact than some of the so-called accented ones. Consider, for example, the line, "From sullen earth sings hymns at heaven's gate," where the word "sings," which in accordance with the conventional iambic scansion would be an unaccented syllable, is really strongly accented, more strongly, indeed, than "earth" which has an accent. As for the division of the line into feet, that is a pure artifice: who, in the actual reading of the above line, would divide the words "sullen" and "heaven" into two parts? The basis of rhythm is, therefore, not word-accent. Value stress is the basis.[Footnote: Throughout the discussion of rhythm I borrow from Mark H. Liddell: _An Introduction to the Study of Poetry._] Certain words, because of their logical or emotional importance, have a greater claim upon the attention, and this inner stress finds outward expression in an increased loudness, duration, and explosiveness of sound. Stress coincides with the word-accent of polysyllabic words because the accent is placed on those syllables, usually the root-syllables, which carry the essential meaning. And this stress is not simply present or absent in a syllable, but greater in some than in others; in iambic rhythm, usually greater in the even than in the preceding odd syllable; in trochaic, greater in the odd than in the immediately preceding even one. The rhythm is rather an undulation of stresses than an alternation of stress and lack of stress, something, therefore, far more complex and variegated than the old scheme would imply. And of this undulation, not the foot, but the line is the unit. The character of the undulation of the whole line determines the type of the rhythm, which may be very different in the case of lines of precisely the same kind of "feet." For example, the line quoted above, "From sullen earth sings hymns at heaven's gate," has a distinctly different rhythm from such another iambic line as "Shall I compare thee to a summer's day?" This difference is due, in part at least, to the fact that the highest peaks of the wave in the former are in the center of the line, in "sings" and "hymns," while in the latter they are at the end, in "summer's" and "day." This undulation of stress is present in prose and in ordinary speech; for there also there is a rise and fall of stress corresponding