Postelsia 62 
Sparganiums, grasses and rushes are commonly 
found along these. 
In many places, strips of meadow land are 
found on either side of the stream, the com- 
position of which merits no special elucidation. 
6 Rivers and Streamlets—The two rivers 
which enter into consideration, the Gordon and 
the San Juan, are streams of considerable vol- 
ume. The former is swift, falling 50 metersin the 
lastere kilometers: Its waters: are» of unusual 
clearness and of low temperature. These factors 
are responsible for the fact that no higher plant 
life is developed in it, at least not throughout 
the extent explored. 
The San Juan on the other hand especially 
in its lower reaches is a much slower flowing 
stream. Along it are found occasional sloughs 
and in these various aquatics like Fontinalts, 
Sparganium, Nymphea and Callitriche are de- 
veloped. 
There are a large number of streams in the 
region, most of which are small brooks that find 
a rapid descent through the numerous gullies 
Oneene: tOLest sinto the -adyormmensea, Under 
