_c_) Vitruvius discussed the _theatrum Latinum_ in chapter 6 of his fifth book and his _theatrum Graecorum_ in chapter 7. The former chapter is longer than the latter by more than a half, and the latter begins with these words: “In the theaters of the Greeks not all things are to be done in the same way” (as in the Roman theaters). The implication is plain that some of the directions in chapter 6 are to be understood as applying also to the Greek theater of chapter 7, and of course the particulars involved would be those which are not modified by the discussion in chapter 7. One of these is the injunction that, for acoustic reasons, the roof of the portico at the top of the auditorium shall be of the same height as the scene-building (v. 6. 4). The scene-building is never built so high as this in Hellenistic theaters, but the rule is often observed in Graeco-Roman and purely Roman theaters.[177] Dörpfeld has advanced several other arguments bearing upon this problem,[178] but in my opinion those just mentioned are sufficient. Now if Vitruvius’ Greek theater is to be identified with the Graeco-Roman structures dating from just before the beginning of the Christian era, it becomes impossible to cite Vitruvius in support of a stage or the use of the proscenium as a stage in Greek theaters of Hellenistic or earlier times. It will be necessary, therefore, to turn back to the fifth century and examine without prejudice the conflicting claims with reference to the presence or absence of a stage at that period. Our discussion of the extant theatrical remains of that century has already made it plain that there is nothing in them which can be employed to prove that there was a stage for the exclusive use of actors. But fortunately the paucity of such evidence is compensated for by the preservation of forty-odd tragedies and comedies of this period. A leading by-product of the stage controversy has been the recognition of the fact that these plays are not only to be taken into consideration together with other evidence but that they must be the final test of all theories based on evidence drawn from other sources. If a given theory will not permit these plays to be “staged” easily and naturally, that theory _ipso facto_ falls to the ground. As von Wilamowitz wrote: “Von dem, was in den Stücken selbst steht, lässt sich nichts abdingen.”[179] Whatever judgment may ultimately be formulated with respect to Dörpfeld’s contributions to scenic antiquities, one of his principal achievements must ever be recognized as the minute, searching, and unprejudiced re-examination of the plays themselves which he provoked.