If any criticism of the Greek plan of holding Thermopylæ is to hold good, it must be based on the existence of the Asopos ravine, which, in spite of the making of the new road, is still used by the natives as a means of communication between the two plains. Why did not Xerxes make use of this road? The reasons for his not using it can only be stated conjecturally. It is quite possible that he never discovered the existence of any sort of road that way until Ephialtes led his men up it to reach the path of the Anopæa. To one standing at the mouth of the ravine, it has all the appearance of a mere torrent bed leading up among the hills. #THE ASOPOS RAVINE.# It is in any case hardly conceivable that any considerable force could make its way through it with the commissariat train which would be its necessary accompaniment. There is only just room for a loaded mule amid the great boulders which block its bed. The Greeks were probably aware of this. It is also probable that the supplies for the Persian army had run somewhat low. It had executed a march of many days without the possibility of direct communication with the fleet, and the taking of the coast road may have become a necessity. Xerxes may well have expected to be able to re-open communications with the fleet almost immediately. He evidently supposed that it would have no difficulty in forcing the channel of the Euripus. In failing, then, to take measures for the defence of this ravine, as well as for the passage of Thermopylæ, it is possible that the Greeks were guilty of an error; but it was an error of a minor kind. The excellence of the general plan of adopting the Thermopylæ and Artemisium line is not affected by it. From the little that is known of those who were responsible for the general conduct of the war, it would seem highly probable that this great design was the work of Themistocles,—a view which is confirmed by Herodotus’ account of the events which happened at Artemisium. This extraordinary man seems, according to the practically unanimous verdict of his own and after times, to have been endowed with unusual capacity, which, in so far as a judgment can now be formed upon the matter, appears to have consisted largely in a most marked and unusual power of insight into the nature of the ruling factor in a great situation. It was combined with an indomitable persistence in attaining the end in view. In the present instance he had to exercise this latter quality to the full. The fact which stands out with most prominence in the general history of the war of 480–479, is that the Peloponnesian Greeks were ever hankering after the Isthmus as the line of defence against the huge Persian expedition. Not merely one, but apparently several fortified lines had been already begun there.