In the back wall of the stage there was one main entrance, and two side doors. It has been maintained, that from them it might be discovered whether an actor played a principal or under part, as in the first case he came in by the main entrance, but in the second, entered from either of the sides. But this should be understood with the proviso, that this must have varied according to the nature of the piece. As the middle scene was generally a palace, in which the principal characters generally of royal descent resided, they naturally came on the stage through the great door, while the servants dwelt in the wings. But besides these three entrances, which were directly opposite to the spectators, and were real doors, with appropriate architectural decorations, there were also four side entrances, to which the name of doors cannot properly apply: two, namely, on the stage on the right and the left, towards the inner angles of the proscenium, and two farther off, in the orchestra, also right and left. The latter were intended properly for the chorus, but were likewise not unfrequently used by the actors, who in such cases ascended to the stage by one or other of the double flight of steps which ran from the orchestra to the middle of the logeum. The entering from the right or the left of itself indicated the place from which the dramatic personages must be supposed to come. The situation of these entrances serves to explain many passages in the ancient dramas, where the persons standing in the middle see some one advancing, long before he approaches them.