52 MR. A. F. BROUN ON THE 
river twists and turns through swamps which often stretch as far 
as the eye ean reach from the top of the mast of a sailing-boat 
or from the upper deck of a steamer. Near many of the bends 
sheets of water, sometimes several square miles in extent, are to 
be seen, and glimpses of other subsidiary channels are also 
obtained. Here and there, especially in the southern portion of 
the Sudd, lines of trees are visible in the far distance, showing 
the limit of the swamps. In places, spits of low land dotted with 
termite-hills, and with some trees and bushes, reach into the 
swamps close to the main channel. There are also occasional 
islands with similar vegetation; one of these is at Hillet en Nuer, 
about halfway through the Sudd, and it served as base camp for 
the recent Sudd operations. A short way to the south of this, 
the clearing of one block has still to be completed, and boats have 
now to make their way through a chain of large lakes. Near 
Shamba the left bank, covered with an open forest of large trees, 
comes to within a mile or so of the main channel. 
The main channel is usually marked by a constant string of 
floating vegetation, whieh may consist of solitary Pistia Stratiotes, 
Linn., of masses of Cyperus Schimperianus, Schrad., and other 
sedges, or of large or small clumps, usually varying according to 
the state of the weather, of Papyrus, Panicum pyramidale, Lam., 
or Typha australis, Schum. & Thonn., the most common being 
twisted strands of rhizomes of Panicum pyramidale, enclosing 
smaller floating weeds such as Azolla nilotica, Decne., and Pistia. 
Starting from Lake No, the channel is, for many miles, lined 
on both sides by a continuous border of Papyrus, dotted here 
and there by occasional clumps of Ambatch (Herminiera Ela- 
phroxylon, Guill. & Perr.). This lining of tightly packed shoots, 
some 10 to 15 feet high, is, in places where water is of the right 
depth, of considerable thickness, but in shallower water large 
stretches of Typha are visible behind the Papyrus hedge. These 
stretches are dotted here and there with clumps of Papyrus and 
Ambatch filling the deeper pools. In this portion of the Sudd 
region Panicum pyramidale is not very common. 
On inspection of the Papyrus fringe near the channel it will 
be found that the mass is tightly bound together by numerous 
twiners and climbers, the most common being Vitis ibuensis, 
Baker, Vigna nilotica, Hook. f., and three species of Ipomea, 
viz. I. Lindleyi, Choisy, I. palmata, Forsk., and J. reptans, Poir. 
The last named has a hollow-jointed rhizome, which floats on the 
