There is within the lyric a sense of symmetry, of poetic consistency, which cannot be measured by Anglo-Saxon rules of prosody. The Indian poet achieves this symmetry in structure by using varied patterns of thought-rhythm; that is, by means of infinitely modified forms of repetition which are as distinctively characteristic of his genius as parallelism was of the ancient Hebrew or as the variations of rhyme and of stanzaic pattern are of the English lyric genius of the last four centuries. The subtle relationship of patterns of thought-rhythm to the whole movement of a poem is often so fugitive as to escape analysis. One origin of these patterns is the most obvious dramatic association which may also determine the direction of the entire thought-movement. Although the dramatic _motif_ shapes both aspects of thought, there is no apparent connection between the progression of an idea and, let us say, the alternating rhythm, except when the alternation becomes incremental. The determining values of pitch and of melodic repetition are also important external factors. Where these influences end, it is difficult to say. So far as this study has proceeded, five characteristic patterns of thought-rhythm appear in Indian lyric poetry. The iterative rhythm appears in the simpler poems, of which the Navaho _Mountain Song_ and _The Omaha Tribal Prayer_ are particularly fine in spirit. The iteration is not always pleasing, sometimes beating with the steady monotony of a kettle drum; but, contrary to reasonable supposition, it does not necessarily indicate a dance song. The alternating rhythm offers the Indian poet some æsthetic relief. It creates a graceful lilt in his verse and often accompanies the quicker movements. This is a universal pattern; but some _Katzina Songs_ of the Hopi and songs of the Zuñi and Pima Indians have markedly achieved this freedom of movement. The elasticity of this form provides an infinite variety of uses, from carrying a pleasant refrain to providing a choric response for the support of a dancing soloist. It has a place in the vocational songs, as well as in the ritual songs of a tribe. There are many variants which employ alternating patterns of thought at the opening and close of a stanza, or with dramatic pose and gesture, as in the Zuñi _Invocation to the Sun-God_, in singing which the Indian mother appeals to the sun, moon, and stars to guide her sleeping infant. Mr. Troyer marks the values of pitch as heightening the rhythmic movements of this song.