250 THE INFLUENCE OF INANIMATE SUEEOUNDINGS. 



straining of the term ; but there can be no doubt whatever that 

 to the southwards it very gradually passes into a fringing reef 

 as characteristic as any to be found in the Philippine Archi- 

 pelago ; and those islands, according to Darwin, may with the 

 greatest certainty be classed among those which, being sur- 

 rounded by fringing reefs, ought to indicate a region of recent 

 upheaval. 



The space included within this southern reef exhibits a 

 few significant peculiarities. No true deep channels occur 

 here, and where they do occur, about the border region near 

 Coroere, they soon disappear as we proceed southwards. The 

 western and eastex-n reef, enclosing the numerous small 

 islands, suri-ounds, on the contrary, an almost horizontal level 

 which from west to east may be at least ten nautical miles 

 across ; and, extending from the southernmost point of Pelelew 

 almost to Coroere, it is about twenty-two miles long. This enor- 

 mous and, as has been said, almost flat surface is traversed in 

 every direction by numerous channels intersecting it at right 

 angles. The average depth of this pool itself may be a few 

 fathoms, but on its northern side it suddenly falls to the depth 

 of the channels there, namely, from fifteen to twenty fathoms. 

 On the east side the reef becomes at last so decidedly a fring- 

 ing reef that natives are always forced to gain the open sea 

 if they wish to visit the villages lying on the east coast. 

 Towards the north again, in the vicinity of Malacca (see Map), 

 this fringing reef becomes a barrier reef. Pinally, it must 

 be observed that here, to the south, the eastern and western 

 reefs show the same differences as I have already described 

 minutely in speaking of Kriangle ; those to the west generally 

 seem to lie deeper than those on the eastern side, and they are 

 strewn with numerous large blocks of dead coral, which are only 

 very seldom covered by water at the highest flood tides ; those 

 on the eastern side lie, on the whole, at a higher level, are formed 

 almost entirely of dead coral, and large blocks of dead coral are 

 never found on their exterior edge. 



VI. The prolongation of the Pelews to the north and 

 south, — It cannot, I think, be disputed that the reefs and islands I 

 ha,ve been describing belong to each other ; but it is very pro- 



