None of the public monuments, of which fragments have been recovered, appear to have been erected before the third century, or, at the earliest, the latter part of the fourth century B.C. But there can be no doubt that similar monuments existed at a much earlier period. These earlier records, together with the choregic inscriptions and the documents in the public archives, must have been the source from which Aristotle derived the information contained in his two books about the contests at the Dionysia. Of these two books the first was called ‘Dionysiac Victories’, and though it is never quoted by ancient writers, it probably contained the same sort of information as the first and third classes of public monuments. The other book was called the ‘Didascaliae’, and is very frequently referred to and quoted from.[187] It contained lists of the poets who competed at each festival, together with the names of the plays they produced. It was therefore similar to the second class of monuments. ‘Didascalia,’ in its dramatic sense, meant originally the teaching and training of a chorus. It then came to denote the play or group of plays produced by a poet at a single festival.[188] Lastly, it was used to denote a record concerning the production of a play or group of plays. It is in this sense that Aristotle used it as the title of his book. The work would not be a mere compilation from existing records and monuments. It must have required some care and research. For instance, when a poet had his plays brought out vicariously, we cannot doubt that the name of the nominal author was entered in the public records, and not that of the real poet. Aristophanes usually brought out his plays in this manner. Then again a poet’s plays were sometimes brought out after his death in the name of his son. In these and similar cases it would be the duty of the compiler of a work like Aristotle’s to correct the mistakes of the public records, and to substitute where necessary the name of the real author of the play. Corrections of this kind were no doubt made by Aristotle and his successors. The Didascaliae of Aristotle is the ultimate source of our information as to the production and the success of the plays of the great Athenian dramatists. Callimachus, the grammarian of Alexandria, wrote a book of a similar kind, based upon Aristotle’s work.[189] It was from Callimachus that Aristophanes, the grammarian, derived the information which he incorporated in his Arguments to the Greek plays.[190] The existing Arguments are mainly fragments of the work of Aristophanes.[191] Thus the process of derivation from Aristotle can be traced step by step. The list of victors at the City Dionysia for the year 458, which was dug up at Athens a few years ago, tallies in every particular with the facts recorded in the Argument to the Agamemnon of Aeschylus.[192] CHAPTER II THE PREPARATION FOR THE CONTESTS § 1. _The Poets._