Arrian and the other historians of Alexander have treated very briefly and vaguely his campaign in the valley of the Indus. Hence it is difficult to trace the course of his operations as he descended from the great confluence at Uchh to Patala where the Indus bifurcates to form the Delta. The distance between these two points, if measured by the course of the river, may be estimated at nearly four hundred miles, yet we find, as Saint-Martin observes, that in the descent not a single distance is indicated, nor a single peculiar feature of the country described which might serve as a sign-post for the direction and guidance of our inquiries. It is at the same time difficult to reconcile the discrepancies found to exist in the accounts transmitted to us, and altogether the search for identities must here mainly concern itself with the names of tribes. In determining how these tribes were collocated it is necessary to take cognisance of the changes which have taken place in the course of the Indus since Alexander’s time. Captain M’Murdo was the first to call attention (in 1834) to these changes, which were not confined to the terminal course of the river, but extended more than two hundred miles above the Delta. He proved that up to the seventh century of our aera the main stream of the Indus, instead of following its present channel, pursued a more direct course to the sea some sixty or seventy miles farther east than it now flows. The old channel, which leaves the present stream at some distance above Bhakar, passes the ruins of Alôr, and then proceeds directly towards the south nearly as far as Brâhmanâbâd, above which it divides into two channels, one rejoining the present course above Haidarâbâd, while the other pursues a south-easterly course towards the Ran of Kachh. The voyage down the lower part of the course took place during the season of the inundation when the plains were laid far and wide under water, and the current was rapid and violent. As the march followed mainly the line of the river the country would appear to the Macedonians extremely rich, fertile, and populous, while the sterility of the regions that lay beyond the reach of the inundations would seldom be brought under their cognisance. In descending the river they could not fail to notice the contrast presented by the plains on its opposite banks, those on the east exhibiting a uniform expanse without any visible boundary, while those on the west were hemmed in by a great mountain rampart which in running southwards gradually approached the Indus till the roots of the hills were laved by its waters. The inhabitants would strike them as being more swarthy in their complexion than the men of the Panjâb, from whom they differed also in their political predilections, as they preferred kingly government to republican independence, and allowed the Brahman to exercise a decisive influence over public life. The descent of the Indus by Alexander, as