Four of these eight-syllable lines combine to form the anushtubh stanza, in which the first two and the last two are more closely connected. In the Rigveda the number of stanzas in this measure amounts to only about one-third of those in the gayatri. This relation is gradually reversed, till we reach the post-Vedic period, when the gayatri is found to have disappeared, and the anushtubh (now generally called çloka) to have become the predominant measure of Sanskrit poetry. A development in the character of this metre may be observed within the Rigveda itself. All its verses in the oldest hymns are the same, being iambic in rhythm. In later hymns, however, a tendency to differentiate the first and third from the second and fourth lines, by making the former non-iambic, begins to show itself. Finally, in the latest hymns of the tenth book the prevalence of the iambic rhythm disappears in the odd lines. Here every possible combination of quantity in the last four syllables is found, but the commonest variation, nearly equalling the iambic in frequency, is [short][long][long][shortlong]. The latter is the regular ending of the first and third line in the post-Vedic çloka. The twelve-syllable line ends thus: [long][short][long][short][short]. Four of these together form the jagati stanza. The trishtubh stanza consists of four lines of eleven syllables, which are practically catalectic jagatis, as they end [long][short][long][shortlong]. These two verses being so closely allied and having the same cadence, are often found mixed in the same stanza. The trishtubh is by far the commonest metre, about two-fifths of the Rigveda being composed in it. Speaking generally, a hymn of the Rigveda consists entirely of stanzas in the same metre. The regular and typical deviation from this rule is to conclude a hymn with a single stanza in a metre different from that of the rest, this being a natural method of distinctly marking its close. A certain number of hymns of the Rigveda consist not merely of a succession of single stanzas, but of equal groups of stanzas. The group consists either of three stanzas in the same simple metre, generally gayatri, or of the combination of two stanzas in different mixed metres. The latter strophic type goes by the name of Pragatha, and is found chiefly in the eighth book of the Rigveda. CHAPTER IV POETRY OF THE RIGVEDA