THE MAKING OF AN ISLAND 145 



sand. As time progressed this sand had crept upwards, filling 

 up the coral branches until it reached the surface. At the sur- 

 face the waves and currents tore at the shifting grains, tossing 

 them about, piling them up and tearing them apart, forming 

 and re-forming the bar with every change of tide. I walked up 

 to the outer edge of the cay and found just this sort of action 

 going on. The magnificent curve of foaming coral reef swept 

 up to the extreme tip of the island where it terminated in a 

 great pile of white sand. The rollers coming in from the sea 

 swirled over this area, churning it into a milky silt which surged 

 back and forth with each ebb and flow of the waves. 



Returning to the little cove and dropping on the sand pre- 

 paratory to getting ready for the swim back to the mainland 

 again I saw the second phase in the drama of the building of 

 an island enacted before my eyes. The tide had reached its 

 lowest ebb and was beginning to flow again. Inch by inch the 

 water crept up the slope of the sand, sending tiny ripples lap- 

 ping gently on the beach. Rolling in these ripples was a long 

 spear-like shaft of reddish wood about a foot in length. The 

 lower end of it was shaped like a javelin, tapering to a smooth 

 point; the upper was peculiarly sheathed with a circle of shriv- 

 eled and torn fibers. The javelin was the radicel of a mangrove 

 seedling, and it had drifted from somewhere on the mainland. 



Mangrove trees live in an area of ever-changing surface, 

 marshes of soft mud, in the treacherous space of the tide lines 

 washed by strong currents and still stronger waves. Their seeds 

 if distributed like those of other trees would soon be washed 

 away, drowned by salt water or smothered in piled up silt. To 

 compensate for this insecurity nature has provided a method 

 of propagation ensuring a firm anchorage in whatever shifting 

 element the tree is to grow. Instead of casting the mature seed 

 to fall and be washed away or buried, the mother tree retains 

 the product of its blossoms until it has produced a long stiff 



