498 Hope . — The ‘ S add' of the Upper Nile . 
of the Gebel, and is consequently much easier to remove. 
At the same time, even in the former river the sudd is at 
times dangerous, especially if it forms down-stream of a 
vessel, and if the latter has to work upon it from its up-stream 
end. The accident to Gessi Pasha’s expedition in 1881 proves 
that even the Bahr-ahGhazal sudd can be an impassable 
obstacle under such circumstances.’ 
How these various plants come to be so massed, in the 
respective rivers, as to form the barrier called ‘ Sadd,’ or 
‘ Sudd,’ is very graphically explained by Sir William Garstin ; 
but the account will not bear abridgement, and it must be 
read in the Report itself. 
The Botany of the ‘ Sadd.’ 
The mention, in Sir William Garstin’s Report, of certain 
plants, as inhabitants of the swamps and lagoons of the Upper 
Nile and its branch the Giraffe Nile, and its tributary the 
Gazelle Nile, and as constitutional parts of the 4 Sadd,’ has 
led to an investigation of these plants from a botanical point 
of view, and the following are the identifications which have 
been made, and notes as to their characteristics. 
The Papyrus Plant. 
The Papyrus plant — Cyperns Papyrus , Linn. — was, in ancient 
times, widely cultivated in the Egyptian Delta, where it was 
used for various purposes, but especially in making a writing 
material ; but it is now extinct in Lower Egypt, and it is 
believed that it was not indigenous there, but probably had 
been introduced from Nubia. A clump of it grows in the tank- 
house in the Royal Botanic Gardens, Kew, with many stems, 
some of which are 9-10 feet in height above the water, while 
others, also in flower, are only about 6 feet high. A very 
characteristic picture of a large clump, backed by a tall grass 
or reed, is to be found in the Gardeners’ Chronicle for 1870, 
p. 314, which was taken from a photograph of the plant as it 
grew on the Anapo River in Sicily. The plant has been re- 
cently and authoritatively dealt with by Mr. C.B. Clarke, F.R.S., 
