THE PACIFIC OCEAN. 2G9 



is excluded. It almost invariably happens that, in 

 the line of reef, one or more openings occur, which, 

 though sometimes narrow and intricate, so as scarcely 

 to allow the passage of a native canoe, are not un- 

 frequently of sufficient width and depth to permit 

 the free ingress of large ships. This is a very re- 

 markable instance of the Divine care over the little 

 creatures which rear these solid structures; they 

 appear to be endowed with an instinctive knowledge, 

 that if the reef were carried uninterruptedly along 

 from one point to another, so as completely to shut 

 in the lagoon, the water within would soon become 

 unfit to support their existence, and would ulti- 

 mately be dried up. The advantage to man of these 

 openings is very great; without them the islands 

 might smile invitingly, but in vain ; no access could 

 be obtained to them by shipping, through the tre- 

 mendous surf by which their shores are lashed ; but 

 by these entrances the lovely lagoons are converted 

 into the most quiet, safe, and commodious havens 

 imaginable, where ships may lie, and wood and 

 water, and refresh their crews, in security, though 

 the tempest howl without. It is a scarcely less 

 beneficent provision that the position of the open- 

 ings is in most cases indicated so as to be visible 

 at a great distance. Had there been merely an 

 opening in the coral rock, it could not have been 

 detected from the sea, except by the diminution 

 of the foaming surf just at that spot; a circumstance 

 that could scarcely be visible, unless the observer 

 were opposite the aperture. But, in general, there 

 is on each side of the passage, a little islet, raised 



z2 



