308 SMITH. 



The number- of large and small islands which it contains is not yet defi- 

 nitely known, but the latest estimate of the Coast and Geodetic Survey 

 places it approximately at 3,000. The total area is about 297,917 square 

 kilometers, the total length of coast line about 18,532 kilometers. Luzon 

 is the largest island, with an area equal to that of England ; Mindanao is 

 next in size, with Leyte, Samar, Panay, JNTegros, Cebu, Palawan, and 

 Mindoro composing a secondary group, each of about the area of the 

 Island of Crete. There are also a host of lesser islands, some of which are 

 nearly as large as those just mentioned, with many others of much smaller 

 dimensions down to mere rocks standing out of the sea. 



The Philippines, with Formosa, Japan, Celebes, Borneo, New Guinea, 

 and, in fact, the majority of the islands of the Malay group are, in my 

 opinion, to be regarded as the rough, shattered ends of the Asiatic conti- 

 nent. They mark the border of the continental plateau, the high points 

 of the wrinkled continental shelf, the crumpled edge of the great land 

 liorst. This view seems to be supported by the fact of the existence of 

 great "deeps" found very close to and east of Japan and the Philippines 

 during the soundings of the Planet. 1 



The main tectonic lines in general run north and south, but minor 

 departures from this direction are to be seen in the lines running through 

 the Islands of Palawan and Mindoro and those in the Sulu group, the 

 Zamboanga Peninsula, and Cebu. The various cordilleras, in my opin- 

 ion, represent the crests of a series of anticlines the major axes of which 

 lie in a north and south line, but the existence of minor cross folding and 

 perhaps faulting causes them to be interrupted. The synclinals, the 

 bottoms of which fall below sea level, exist as narrow straits common 

 throughout the Archipelago. The strait between ISTegros and Cebu marks 

 such a synclinal. A similar trough, once occupied by water, exists on 

 Luzon between the Zambales Eange in the western part of the island 

 and the Eastern Cordillera. This is now a long, wide, flat area known as 

 the great central plain of Luzon. The lines connecting the various active 

 and extinct volcanoes correspond very closely to the main tectonic lines. 



I shall first, in considering the various physiographic units, take up 

 the several types of plains, because in them we' find the greatest human 

 activity. 



COASTAL PLAINS. 



The various units of the Archipelago are, as is the case with many 

 recent islands, characteristically lacking in a'ny considerable development 

 of coastal plain. The country is backward in commercial development 

 probably because of this fact more than any other. Nearly everywhere 

 the mountains very closely border the coast. Coral reefs are found 



'Annalen der Hydrographie und Maritimen Meteorologie (1906), Dec, 556. 



