The story told by Herodotus is probably as much a product of the imagination as that of Ctesias, though it reads more like actual history. He says that the Scythians retreated northward, sending their wives and children before them in wagons, and destroying the wells and ruining the harvests as they went, so that little was left for the invaders to eat and drink. On what the vast host lived we do not know, nor how they crossed the various rivers in their route. With such trifling considerations as these the historians of that day did not concern themselves. There were skirmishes and combats of horsemen, but the Scythian king took care to avoid any general battle. Darius sent him a herald and taunted him with cowardice, but King Idanthyrsus sent word back that if the Persians should come and destroy the tombs of the forefathers of the Scythians they would learn whether they were cowards or not. Day by day the monster Persian army advanced, and day by day its difficulties increased, until its situation grew serious indeed. The Scythians declined battle still, but Idanthyrsus sent to his distressed foe the present of a bird, a mouse, a frog, and five arrows. This signified, according to the historian, "Unless you take to the air, like a bird; to the earth, like a mouse; or to the water, like a frog, you will become the victim of the Scythian arrows." This warning frightened Darius. In truth, he was in a desperate strait. Leaving the sick and weak part of his army encamped with the asses he had brought,--animals unknown to the Scythians, who were alarmed by their braying,--he began a hasty retreat towards his bridge of boats. But rapidly as he could march, the swifter Scythians reached the bridge before him, and counselled with the Ionian Greeks, who had been left in charge, and who were conquered subjects of the Persian king, to break down the bridge and leave Darius and his army to their fate. And now we get back into real history again. The story of what happened in Scythia is all romance. All we really know is that the expedition failed, and what was left of the army came back to the Danube in hasty retreat. And here comes in an interesting part of the narrative. The fleet of Darius was largely made up of the ships of the Ionians of Asia Minor, who had long been Persian subjects. It was they who had bridged the Danube, and who were left to guard the bridge. After Darius had crossed the bridge, on his march north, he ordered the Ionians to break it down and follow him into Scythia, leaving only the rowers and seamen in the ships. But one of his Greek generals advised him to let the bridge stand under guard of its builders, saying that evil fortune might come to the king's army through the guile and shrewdness of the Scythians.