128 
PALAWAN. 
five miles before the base of the mountains are reached have been formed chiefly by the 
agency of coral reefs. The country directly behind Taguso is level for about two miles 
inland, where a sudden rise of about twenty feet takes place, when another extensive plain 
stretches to the foot of the mountains. 
Land-making in Palawan is carried on to a small extent by the mangrove-swamps, 
which are unable to stretch out to sea, chiefly owing to the coral formation around the 
coasts—these great land-makers being unable to do much, except in protected bays or 
straits, where the mud collected is not washed aw’ay by storms. The great makers of these 
plains are the small rivers, which do not build up land so much by their fluviatile deposits, 
but chiefly through the opposing action of the sea itself. To explain my meaning the 
better I have drawn the accompanying diagram. 
The river flowing in a direct line into the sea meets with the opposing waters, and by 
this action a sand-bar is formed directly across the mouth. The course of these rivers 
being short, for the greater part of the year the force of their flow is small, so that the bar 
is formed close to the shore, unlike the great Bornean rivers, where the bar may extend 
several miles out to sea. This bar once formed, the river’s force is insufficient to disperse 
it, so it gradually increases, by sand and coral debris thrown up by the sea and by an 
occasional tree-trunk. Soon the river’s course flows to the right or left and runs parallel 
with the bar; the force being insufficient to keep open two mouths, the unused channel 
gradually becomes blocked. The river gradually increases its length, running parallel with 
the bar, easily cutting away the sandy shore against which its course is now directed. 
Meanwhile the further extremity of the bar has become joined to the mainland, and 
shortly supports a vigorous vegetable growth of plants and shrubs especially adapted to the 
shore. Amongst these plants I must especially mention a long rope-like stemmed convol¬ 
vulus with pretty pink flowers—the runners of this plant attaining a length of 30 yards or 
more, rooted here and there along their length in the sand. When once such a growth 
becomes established, our sand-bar is substantially strengthened. In the meanwhile the 
bank, at the point where the river formerly debouched, has been gradually weakened by the 
