in any real sense, Ctesiphon and Qaṣr-i-Shîrîn, and at Ctesiphon we know only the great hall of audience--together with a fairly accurate guess at its flanking chambers. Before we can say that the extensive wings, which at Qaṣr-i-Shîrîn were added to the khilâni palace, were not a natural development (and they are planned on principles which are entirely oriental) we must have a clear conception of that which lay about the great hall at Ctesiphon, of the palace at Dastadjird which Heraclius committed to the flames, and of the palaces in the Zohâb district. The oriental palace, in the form which it had received from Chosroës and Nu’mânid, laid a strong hold upon the imagination of the East. In the Days of Ignorance the Arab of the desert entered its courts with praise; in the days of conquest he divided its spoils with his fellow soldiers, and sent a part to Mekkah, glorying in the God-given strength which had dispossessed the kings of the earth. Not by literary evidence alone can the deep impression which it created be measured. It gave birth to the Syrian ḥîrahs and to the stupendous residences of the Abbâsids. On the Syrian side of the desert there is another element to be considered, the Roman legionary camp, and this too had a centre and two wings. The truth is that any complex of buildings laid out on an ordered plan falls almost inevitably into this disposition. The palace of the Flavians on the Palatine had a centre and two wings, yet it was not for that reason derived from the khilâni or related to the oriental palaces. Its ancestor was the Greek peristyle house which goes back in turn to the megaron palaces of Mycenae and Tiryns and Troy. Neither were Qaṣr-i-Shîrîn and its offspring in the Syrian desert derived from the limes camp. Gradually but surely, while Rome still held the Syrian frontier, or rather while Rûm--the Hellenistic, the Byzantine Rome, itself half-orientalized--held it, the ancient Asiatic scheme invaded the limes fortress, pushed out the Praetorium, or pushed it back against the encompassing wall, which had become an indispensable requisite, and having grouped its baits after its own fashion, left a court over. The union of both sides of the desert under the hand of a single ruler quickened the process. Neither the Roman Qasṭal nor the Umayyad Ṭûbah are palaces on the Persian ḥîrah plan; then suddenly Kharâneh and Mshattâ spring into being, uniting the oriental traditions of the Mesopotamian side of the desert with oriental traditions which had developed independently from the same root on the Syrian side. The Syrian architects were masters of a more scientific technique, for they had been trained in a Graeco-Roman school. They taught their Mesopotamian brothers, and even the builders of remote Ukhaiḍir had learnt how to lay a cross vault.