510 Hope . — The ‘ Sadci ’ of the Upper Nile. 
the Nile, and showed how similar the vegetation is in the two 
localities. During the floods, Mr. Clarke says, the only 
means of communication is by water ; and away from the 
main streams the inhabitants can get about nowhere except 
from point to point where the villages are built on isolated, 
artificially-raised, mounds, or on river banks. This they do 
along straight lanes through the floating vegetation, which are 
kept open by the boat traffic. 
Mr. Clarke points out that the main difference between 
the Bengal floating vegetation and the Nile ‘ Sadd * is that 
the first-named grows in water which is practically at rest 
(it really moves in mass, though extremely slowly, from 
north-west to south-east), but the floating vegetation if forced 
into the main rivers is lost owing to their vast width ; whereas 
the‘ Sadd ’ plants of the Nile, though reared in the still waters 
of the lakes and lagoons, are broken off into clumps and 
carried into the river by the strong winds which accompany 
the annual rise of the river, and there become potent for 
mischief. The interesting point to Mr. Clarke is the remark- 
able way in which some of the African ‘ Sadd ’ plants are 
represented in Bengal by closely allied ‘ representative ’ species. 
The two ‘Sadd’ floating species of Cyperus ( C '. colymbates , 
Kotsc. and Peyr., and C. nudicaulis , Poir.), have in Bengal 
two representatives, C. cephalotes , Vahl., and C. platystylis , 
R.Br., the seeds of which float and germinate in the water. 
The seeds of C. papyrus , and some other species which at all 
events begin their life rooted in the ground, are heavy and sink 
to the bottom, there to germinate in the mud. 
The representative of ‘Ambatch’ {Herminiera elaphroxylon , 
Guill. and Perrot) in Bengal Mr. Clarke finds in Aeschynomene 
aspera , Linn., also a leguminous plant, of a genus which stands 
next to Herminiera in Bentham and Hooker’s ‘ Genera Plant- 
arum/ Herminiera is, he says, only Aeschynomene writ large. 
The wood, or ‘ pith,’ of this shrub is the well-known ‘ Sola ’ of 
Bengal, which is used for making sun-hats, swimming-jackets, 
and covers under which to keep iced drinks cool, and for 
many other purposes where elasticity and lightness are 
