There are systems of rhythm—early Latin probably, early Teutonic certainly—to which this prosody does not apply, except partially, if it applies at all. But all poetries that depend upon _metre_—that is to say, on the arrangement of equivalenced syllabic values in certain recurring orders—are governed by the laws which the Greeks discovered, and which the Greeks exemplified. On this side, therefore (and it is a most important side), the literary critic owes them everything. They have furnished him with every tool that he requires for taking to pieces the mechanism of the _Ancient Mariner_, as well as of the choruses, of the _Agamemnon_, of the odes of Hugo as well as of those of Pindar, of the _Nordsee_ of Heine as of the fragments of Sappho and Alcæus. And it is not at all improbable that if we possessed more of their work on prose rhythm, that subject also, and the kindred one of the so-called accentual rhythms of Latin and early Teutonic verse, would be almost as much facilitated. When we pass beyond these elements and come to the general subject of Rhetoric (which, it must be remembered, in at least some places is recognised as covering the whole of _graphica lexis_) and Poetics, the advances in both departments, but especially in the latter, are still very great, if not so great proportionately. We have only one poetical kind—that of Tragedy, as understood by the Greeks themselves, and practised by the three great tragedians—which has been subjected to a thorough critical examination in extant text. But then this examination is so thorough that, in reference to the particular kind, hardly anything has been added since. We have, in reference to the capital example of another kind, Epic (again as understood by the Greeks), a large variety of treatments, from Aristotle to Longinus, which, if they do not give as firm and systematic a theory of this as of the former, yet go far towards doing so. Of the remaining divisions of poetry we learn, it must be confessed, less from the Greeks; and even in examples we are, except in so far as the Ode and the Idyl are concerned, very lamentably ill supplied. But in the one case, as in the other, the fragments are precious. And it may in such a book as the present, be pardonable once more to point to the feather in the cap of Criticism furnished by the fact that, but for two critics, we should be destitute of these two great lyrics of Sappho which, outside the contents of drama, are the crown and flower of Greek lyrical poetry.