In essentials the interior arrangements of all the churches are similar: east of the pillars that support the central dome, the church is divided by the ikonostas--a development of the rood-screen--which separates the officiating priests from the worshippers. In old churches seats were placed round the walls and stalls provided for persons of high rank, but for long it has been customary for the congregation to stand during the services. Behind the ikonostas is the sanctuary; there females may not enter, nor any male if physically imperfect; it is disclosed to the worshippers during the celebration of Mass by opening the "Royal Doors" in the centre of the ikonostas. There are in all churches sacred ikons, having the place of honour on the ikonostas; decorative and illustrative pictures are placed there also, and the same--as frescoes, or otherwise--around the central columns and along the walls of the church. Usually the north wall is appointed for those pertaining to the saint to whom the church is dedicated; the south wall to the seven councils, the west to other sacred subjects. Although the ikonostas is the equivalent of the rood-screen in the old English churches, it is not only always a fixture, but sometimes a solid partition of masonry, being really that barrier which shuts off the Holy of Holies, that may be entered by the consecrated priests alone, from the rest of the temple. It is always decorated, but the high ikonostas, having five, or even seven, tiers of pictures is a development later than the fifteenth century. The "Royal Doors" must have representations of the Annunciation and the four Evangelists, since through this entrance came the glad tidings of the Eucharist; right and left of the doors the Saviour and the Madonna; also, usually, Adam, as the first fallen, and the Penitent Thief as the first redeemed; above, the Trinity; Abraham entertaining the three angels and John the Baptist most frequently figure on the screen, and, on the pillars facing the entrance, the Publican and Pharisee as symbolic of an all inclusive congregation of worshippers. In the Sanctuary is a tabernacle or Sinai, upon the altar, and over it a baldachino on which the cross is laid horizontally--or nearly so. In the apse behind [Illustration: CHURCH OF THE NATIVITY AND FLIGHT] the altar is the _thronos_ or seat of the head of the church, with other seats for priests on both sides; the choir is a raised dais before the ikonostas.