From the point where the Bokharan province of Kulab becomes separated by the Oxus river from the Afghan districts of Rustak and Kataghan the channel of the stream is contained no longer by the walls of the mountains. Broad streams, from the Trans-Alai range in one direction and the highlands of Karategin in another, join the Oxus, the main river at once beginning to adopt an uncertain channel. Numerous feeders appear on both banks at this part of its course. The Kulab and Surkhab-Waksh-Kizil-su join it in broad muddy streams from the Karategin uplands, until the river, changing its character altogether, divides itself into many channels where the hills fail to confine it. In addition to the two tributaries just mentioned as appearing on the right bank, there are three others, the Kafirnahan, the Surkhan, and the Darban. These are contributed from Bokhara; while, on the left bank, Badakshan dismisses the Kokcha and the Kunduz-Ghori-Khanabad-Aksarai to a meeting with the main stream. In earlier times, when there were fewer settlements and the demand for purposes of irrigation was not so great, the Amu Daria possessed, both on the north and on the south, other tributaries, the waters of which are now entirely diverted to the fields. In these middle as also in the upper reaches of the river but little of the main stream is utilised by villagers, the inhabitants of the settlements in the valleys threaded by the Oxus supplying their agricultural necessities from the smaller streams. West of Kunduz, for a distance of nearly 700 miles, the drainage of the hills to the south of the river is lost in the plains of Afghan Turkestan; but on the Bokharan side the extensive canalisation, which is such a prominent feature, causes many of the streams to be exhausted before they have had opportunity to effect a junction with the Amu Daria. It is not until near Pitniak that any important diversion of the waters of the Oxus for cultivation is made. At that point the great division of the stream for the requirements of the Khivan oasis occurs, a general discharge of 125,000 cubic feet per second being deflected in order to supply a system of canals by which over 4000 square miles of fertile alluvial land are kept in tillage.