124 A Ride across the Vega 
Here and there, some of the lowest-lying ground remains under 
water until the torrid heat of the August sun effectually dries it 
up; the dense reeds are then cut by the inhabitants for thatching 
their cottages or are exported to be made into bottle-casings. 
These isolated pieces of water or /agunas so long as they last 
form sanctuaries, not alone for many water-birds but for numerous 
fish and reptiles. 
A RIVER IN THE PLAINS: EVENING. 
The plains are intersected by small rivers which, owing their 
supply as they do to the rainfall in the distant sierras, are usually 
full from the time of the autumnal rains until the spring. Every 
heavy rainstorm causes them to flood bank-high and not seldom 
to overflow. Since the waters when in flood are heavily charged 
with suspended matter, which quickly settles whenever the current 
is lessened, the effect of these continuous overflows is to make a 
deposit of silt and mud along the top of the river banks, which 
are by this means at places raised several feet higher than the 
