FRINGING REEFS OF THE PHILIPPINES 517 



chart of coral reefs (1912) gives the fringes of the Philippines a much 

 greater breadth than they usually possess. 



The existence of earlier formed reefs at lower levels, now drowned, is 

 highly probable on many of the Philippine Islands; for the absence of 

 strong cliffs on the headlands of their embayed shores indicates the pres- 

 ence of protecting reefs while the coasts were suffering erosion before 

 their recent subsidence; thus all the more does the absence of an exten- 

 sive system of offshore barrier reefs, which should have grown up from 

 the preexistent reefs during a slow subsidence, indicate that subsidence 

 was more rapid than reef upgrowth. 'Moreover, the submarine platforms 

 that border some of the islands are best explained as submerged and 

 more or less aggraded reef plains, on the outer margin of which new 

 barrier reefs have failed to reach the present surface because of rapid and 

 recent subsidence ; indeed, some of the platforms have no sign of upgrow- 

 ing marginal reefs, and these must have been submerged with unusual 

 rapidity at a very recent date. It is quite possible that some of the shore- 

 lines here treated as showing recent submergence may have afterwards 

 emerged by a moderate amount from a previous greater submergence of 

 moderate duration, for charts do not always suffice to distinguish between 

 these two cases; but in either case, the fringing reefs would rest uncon- 

 formably on their foundations. 



The facts here discovered seem to me to give strong confirmation to 

 Darwin's views ; not only so, they show that, after the many other move- 

 ments the Philippines have suffered, the recent subsidence of many of 

 the islands has been more rapid than reef upgrowth, and hence more rapid 

 than the subsidence of most of the islands in the central Pacific around 

 which barrier reefs or above which atolls are commonly found. In this 

 respect I believe the recent history of the Philippines to be representative 

 of that of the other archipelagoes of the western Pacific, where, in spite 

 of the evidence for submergence given by strongly embayed shorelines, 

 barrier reefs are imperfectly developed and atolls are rare. 



The smaller islands of the archipelagoes, although often possessing 

 embayed shorelines, are not as a rule encircled by well developed barrier 

 reefs, such as those which characteristically surround the islands of the 

 Fiji and the Society groups. No such extensive barriers as those of New 

 Caledonia and the Queensland coast of Australia are known around the 

 larger islands of the archipelagoes today. Nowhere are the larger islands 

 bordered at present with barrier reefs at all comparable to the barrier 

 which, when certain islands stood higher in the recent past, fronted the 

 northwest coast of Palawan for 300 miles, as further stated below; 

 nowhere at present is there an atoll or almost-atoll comparable to the 



