the Danube, with which the assertion of Herodotus agrees, that the Scoloti retired before Darius to the border of the land of the Agathyrsi, and the lake out of which the Tyras rises, but no further. By the lake out of which the Tyras rises we can hardly understand the lakes at Lemberg, for Darius could scarcely have come so far to the west. The marshes at the source of the Bug are probably meant, which as the crow flies are 325 miles from Reni, on the Danube. If the Scoloti ventured to retire but a little way from the river courses, the Persians retired still less. Hence the retreat of the Scythians and the advance of Darius must have proceeded up the Pruth, through Bessarabia to Podolia as far as the marshes on the upper Dniester in which the Bug rises, where Herodotus represents the two armies as encamping opposite each other, or as far as the marshes of the Prypet. The answer which Herodotus puts in the mouth of Idanthyrsus--that Darius should attack the tombs of the kings (on the rapids of the Dniester) and then the Scythians would fight, has a meaning, if Darius was far from the centre of Scythia, and the message was sent to him when in the neighbourhood of the source of the Bug or the Prypet; it was without meaning if he had already traversed the whole land of Scythia as far as the Don and the Volga. Want of provisions for man and beast far more than the want of water would have compelled him to return. Had the Scythians previously surrounded the army of Darius on all sides, they would have thrown themselves with impunity in full force on his rear when retreating. If everything left behind through weariness and sickness had fallen into their hands, they would now not merely hinder the retreat but greatly endanger it. As soon as the communications with the Danube were completely closed (Strabo tells us that Darius was cut off in the desert of the Getae), Darius must have been in alarm whether the fidelity of the tyrants or their desire to maintain their position in their own cities was strong enough to keep them at the bridge, and if this were the case whether they could induce their crews to remain.