44 THE CORAL REEFS OF THE MALDIVES. 



a short way over it, the greater part of the flat being covered by dead 

 corals overgrown with Nullipores. The sand beaches surrounding the 

 island are steep, from six to seven feet in height. The central part of 

 the island is lower than the top of the beaches which surround it, form- 

 ing a shallow sink from twelve to eighteen inches or more in depth. 

 Considerable moisture accumulates in this central sink, and in the rainy 

 season a pool is probably formed of more or less brackish water. This 

 structure is most characteristic of the islands of the Maldives, whether 

 they occur in the interior of the great sheets of enclosed waters or on the 

 outer rims of the plateaus. The sink has been formed by the washing up 

 of the beaches round a central area, as we have seen it in the Paumotus and 

 elsewhere in other Pacific atolls. Before the vegetation became too dense, 

 beach sand was blown towards the interior and partly filled the central area, 

 until this was prevented by the growth of bushes and shrubs, when the 

 beaches merely increased in height and the sand of the upper ridge of 

 the beach was driven sparingly towards the centre of the island, or its 

 further passage stopped by the belt of denser vegetation which had come 

 up on the higher parts of the coral sand beach. The island of Male has gradu- 

 ally developed and been formed much in the same manner as this island. 



The corals growing on the slopes of this island are marked for their 

 luxuriance ; they grow as abundantly as they do on the sea face of any 

 atoll. This is in striking contrast to their scanty development in the 

 interior of typical lagoons. It can readily be explained from the great 

 depths of the passes and the great mass and purity of the water passing 

 into the interior of the enclosed basin of North Male. Throughout the 

 northern and central Maldives corals grow in great profusion on the slopes 

 of the islands and faros within the enclosed basins of the group. The 

 branching corals consist mainly of species of Madrepores, of Pocillopores, 

 and Millepores. While the massive corals are usually Astreans, Porites, 

 and the like, Maeandrinte are not common, 



The vegetation of this island is remarkably fine. In spite of its small size 

 large trees are found upon it. It is a favorite resort for flying foxes ; its 

 aspect is in striking contrast to the meagre flora found on similar islands in 

 the Paumotus, Ellice, or Gilbert Islands. 



