(iii) The architectural remains. Dörpfeld sums up his celebrated architectural researches thus. No theatre survives from the fifth century, but the theatre of Lycurgus (fourth century) belongs to a period when the plays of that century were still acted in the old manner. Also we possess numerous buildings which represent the rather later form of the theatre (the building with fixed proscenium), and which belong to that period to which the remarks of Vitruvius apply. From the Lycurgean theatre we learn that there was no stage high or low. A platform for actor or orator is only necessary when the audience are all on a flat area. If they sit on a slope, a stage is more inconvenient than if the speaker stands on the ground.[165] And so, in the earliest times, when there was no sloping auditorium, Thespis, for example, performed upon a cart. In Italy the slope came into use only late, and the stage had been widely adopted before that time—for there was no chorus to provide for. When the Greek theatre was introduced into Italy, the Roman form was invented. They did not abandon their own stage, but divided the Greek orchestra into two parts of different height. The farther half, now superfluous (the chorus having vanished) could be used for spectators or gladiators. This portion was (in earlier theatres of the true Greek type) excavated and filled with fresh seats. The stage was, of course, not made higher than the lowest eyes. The nature of the proscenium in Greek theatres was not suitable for the supporting wall of a stage. It would be absurd to see a temple in the air above a colonnade.[166] Again, it was impossible to act on top of the proscenium. The fear of falling, when the actor wore a mask and was forced to approach the edge in order to be well seen by the lowest spectators, would spoil his acting. Finally, why was the proscenium-front not a tangent of the orchestra circle? It should have been brought as far forward as possible if they acted on top of it. To sum up. The orchestra in the earliest period was the place of the chorus and the actors. It kept that function when the _scēnē_ was erected beside it as a background. The chorus used the whole circle, the actors only part of it and the ground which lay in front of the _scēnē_. No change in this arrangement was made later. The actors in Roman times, of course, stood above the level of the excavated semicircle. But they remained throughout at the same distance from the spectators[167] and at the same level—that of the old orchestra.