DISTRIBUTION OF REEFS. 143 
able. Occasional traces, sometimes amounting to a fringing reef, 
occur along Luzon and the other Philippines. 
We coasted by the west shore of Luzon to Manilla, and thence by 
Luban, Mindoro, Panay, to Caldera, near Samboangan in Mindanao ; 
and through this distance, no reefs were distinguished, as would have 
been the case had there been any of much extent. At the last-men- 
tioned place we found coral pebbles on the beach, and by dredging 
obtained living specimens in six to eight fathoms of water. ‘The only 
large reefs were those between Mindoro and the Calaminianes. There 
are fringing reefs at Singapore. The islands of Borneo, Celebes, Java, 
and Sumatra, according 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. Quel- 
paert’s Island, south of Corea, in 34° N., is described as having coral 
about it; and this has been confirmed by late information. 
Why should the reefs of the East India Archipelago be so limited 
in extent, and large parts be almost destitute, notwithstanding their 
situation in the warmest seas of the ocean, and in the most favourable 
region for tropical productions? We are not prepared for a full 
auswer to this inquiry, which demands a thorough knowledge of the 
shores, as well as of the currents, and the former and present condi- 
tion of volcanic fires. From personal 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 unfavourable 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, exceed- 
ing, for the area, every other part of the world: and this fact must 
have had influence on the formation of coral reefs, though we have not 
the data for fixing the extent of the influence. Of the numerous 
vents which have been in action, several still make themselves felt 
over wide areas. ‘The Sooloo Islands are about one hundred in num- 
ber, and nearly all are pointed with volcanic cones; and while some 
have the broken declivities that are marks of age, others have regular 
slopes, as if but just now extinguished; a dozen of these cones may 
