Aristophanic Comedy falls structurally into marked divisions, episodic and epirrhematic. The first is a very simple method of composition consisting of short iambic scenes, connected by choral stasima which are more or less relevant to the action. As a general rule these episodes occupy the second half of the play between the Parabasis and Exodos, and, since they show the hero enjoying the fruits of his earlier struggles, contribute little to the development of the plot. Many of the Comic Fragments in trimeters are probably taken from episodes, but any attempt to classify them would add nothing to knowledge of a play from the structural viewpoint. The case is otherwise with the epirrhematic parts of Comedy. These are of complicated structure, marked by the use of the syzygy, i.e. the correspondence of odes and epirrhemes on the plan abab and also by the use of the tetrameter, which is confined to these sections. They may be further differentiated among themselves by the metre used. In the Parodos anapaests, iambs and trochees are found, in the Agon iambs and anapaests, in the parabatic syzygy only trochees, in the ⋯πλο⋯ν anapaestic and aeolic tetrameters. Taking the use of the tetrameter as guide it is possible to classify certain of the Comic Fragments, and subject matter and the criterion of metre often give some indication of the particular epirrhematic section from which they are taken. Prologue and Exodos stand outside the scheme of both episodic and epirrhematic composition, being structurally self-contained. The former consists of iambic trimeters, not a simple means of differentiation, but sometimes subject matter affords convincing points of analogy with the Aristophanic Prologue. The Exodos shows a great variety of metres, but here again subject matter and Aristophanic analogy are of great value in classification.