144 CORALS AXD CORAL ISLANDS. 



to half a mile, generally running nearly parallel with the shore, 

 and at top were from a fourth to half an inch wide. These 

 fissures are not essential features of the reef They are prob- 

 ably a result of a subterranean movement or shaking. 



The beach consists of coral pebbles or sand, with some worn 

 shells, and occasionally the exuvi^ of crabs and bones of 

 fishes. Owing to its whiteness, and the contrast it affords to 

 the massy verdure above, it is a remarkable feature in the 

 distant view of these islands, and often seemed like an artificial 

 wall or embankment running parallel with the shores. On 

 ""lermont Tonnerre, the first of these islands visited by us, t))e 

 natives seen from shipboard, standing spear in hand along the 

 top of the beach, were believed by some to be keeping patrol 

 on the ramparts of a kind of fortification. This deception 

 arose from the dazzling whiteness of the coral sand, in conse- 

 quence of which, the slope of the beach was not distinguished 

 in the distant view. 



The emerged land beyond the beach, in its earliest stage, 

 when barely raised above the tides, appears like a vast field of 

 ruins. Angular masses of coral rock, varying in dimensions 

 from one to a hundred cubic feet, lie piled together in the 

 utmost confusion ; and they are so blackened by exposure, or 

 from incrusting lichens, as to resemble the clinkers of Mauna 

 Loa ; moreover, they ring like metal under the hammer. Such 

 regions may be traversed by leaping from block to block, with 

 the risk of falling into the many recesses among the huge 

 masses. On breaking an edge from the black masses, the 

 usual white colour of coral is at once apparent. Some of the 

 blocks, measuring five or six feet in each of their dimensions, 

 were portions of single individual corals ; while others had the 

 usual conglomerate character of the reef-rock, or, in other 

 words, were fragments torn by the waves from the reef-rock. 



In the next stage, coral sand has found lodgment among the 

 blocks ; and although so scantily supplied as hardly to be de 

 tected without close attention, some seeds have taken root, and 

 vines, purslane, and a few shrubs have begun to grow, relieving 

 the scene, by their green leaves, of much of its desolate aspect. 



