GEOGRAPHICAL DISTRIBUTION. 105 



Another East Indian coral reef region, of some extent, is the 

 Sooloo Sea, between Mindanao and the north of Borneo. Yet 

 the reefs are mostly submerged. We saw no wide platforms 

 bordering the high lands, like those of the Pacific. There are, 

 however, some small coral islets in the Balabac Passage. 



In other parts of the East Indies, coral reefs are quite incon- 

 siderable. Occasional traces, sometimes amounting to a fringing 

 reef, occur along Luzon and the other Philippines. 



We coasted by the west shore of Luzon to Manila, and thence 

 by Luban, Mindoro, Panay, to Caldera, near Samboangan in Min- 

 danao ; and through this distance, no reefs were distinguished, 

 as would have been the case had there been any of much extent. 

 At the last mentioned place we found coral pebbles on the beach, 

 and by dredging obtained living specimens in six to eight fath- 

 oms of water. The only large reefs were those between Min- 

 doro and the Calaminianes. There are fringing reefs at Singa- 

 pore. The islands of Borneo, Celebes, Java, and Sumatra, ac- 

 cording to all the authorities seen by the writer, have but few 

 coral patches about their shores, although affording long lines of 

 coast for their growth. In the China Seas, there are numerous 

 shoals, banks and island reefs of coral. Moreover, shore-reefs 

 occur about Loochoo, and the islands between it and Formosa. 

 But the whole eastern coast of China appears to be without 

 coral. Q,uelpaert's island, south of Corea, in 34° N., is described 

 as having coral about it j and this has been confirmed by late in- 

 formation. 



Why should the reefs of the East India Archipelago be so 

 limited in extent, and large parts be almost destitute, notwith- 

 standing their situation in the warmest seas of the ocean, and in 

 the most favorable region for tropical productions? We are not 

 prepared for a full answer to this inquiry, which demands a thor- 

 ough knowledge of the shores, as well as of the currents, and of 

 the former and present condition of volcanic fires. From per- 

 sonal observation, we may reply satisfactorily, as far as regards 

 part of the southern half of the east coast of Sumatra. This 

 coast is low, and sandy or muddy, and thus affords the most un- 

 favorable place for zoophytes. A strong current sweeps through 

 the straits of Banka, which keeps the water muddy, and the 

 shores in constant change. The same cause may operate on the 

 coasts of other islands, but we are ignorant to what extent. 



The East Indies have been remarkable for their volcanoes, ex- 

 ceeding, for the area, every other part of the world : and this 

 fact must have influence on the formation of coral reefs, though 

 we have not the data for fixing the extent of the influence. Of 

 the thousand vents which have been in action, several still make 

 themselves felt over wide areas. The Sooloo islands are about 

 one hundred in number, and nearly all are pointed with volcanic 



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