Physical Geography. 19 



globe. Their width is about fifty miles ; but, for a space of 

 two hundred on each side of them, evidences of subterranean 

 action are to be found in recently elevated coral rock, or in 

 barrier coral reefs, indicating recent submergence. In the 

 very centre or focus of the great curve of volcanoes is placed 

 the large island of Borneo, in which no sign of recent volcanic 

 action has yet been observed, and where earthquakes, so char- 

 acteristic of the surrounding regions, are entirely unknown. 

 The equally large island of New Guinea occupies another 

 quiescent area, on which no sign of volcanic action has yet 

 been discovered. With the exception of the eastern end of 

 its northern peninsula, the large and curiously-shaped island 

 of Celebes is also entirely free from volcanoes ; and there is 

 some reason to believe that the volcanic portion has once 

 formed a separate island. The Malay Peninsula is also non- 

 volcanic. 



The first and most obvious division of the Archipelago 

 would therefore be into quiescent and volcanic regions, and 

 it might, perhaps, be expected that such a division would cor- 

 respond to some differences in the character of the vegetation 

 and the forms of life. This is the case, however, to a very 

 limited extent ; and we shall presently see that, although this 

 development of subterranean fires is on so vast a scale, has 

 piled up chains of mountains ten or twelve thousand feet high, 

 has broken up continents and raised up islands from the 

 ocean, yet it has all the character of a recent action, which has 

 not yet succeeded in obliterating the traces of a more ancient 

 distribution of land and water. 



Controls of Vegetation. — Placed immediately upon the 

 Equator and surrounded by extensive oceans, it is not surpris- 

 ing that the various islands of the Archipelago should be al- 

 most always clothed with a forest vegetation from the level 

 of the sea to the summits of the loftiest mountains. This is 

 the general rule. Sumatra, New Guinea, Borneo, the Philip- 

 pines and the Moluccas, and the uncultivated parts of Java 

 and Celebes, are all forest countries, except a few small and 

 unimportant tracts, due perhaps, in some cases, to ancient cul- 

 tivation or accidental fires. To this, however, there is one 

 important exception in the island of Timor and all the small- 

 er islands around it, in which there is absolutely no forest such 



