CHAP, r.] 



PHYSICAL GEOGUAmr. 



13 



the vast majority) are geiiLTally as strictly limited by 

 straits and arms of tlie sua as are quadrupeds themselves. 

 As an instance, amonj? the islands of "vvhicb I am now 

 speaking, it is a remarkable fact that Java possesses 

 numerous birds wliich never pass over to Sumatra, though 

 they are separated by a strait only fifteen miles wide, and 

 with islands in mid-channel, Java, iu fact, possesses more 

 birds and insects peculiar to itself than eitbey Sumatia 

 or Borneo, and this would indicate tliat it was earlii^dt 

 separated from the continent; next in organic indi\'i 

 duality is Borneo, while Sumatra is so nearly identical 

 in all its animal forms with the peninsula of Malacca, 

 that we may safely conclude it to have been the most 

 recently dismembered island. 



The general result therefore at wliich we arrive is, that 

 the great islands of Java, Sumatra, and Borneo resemble 

 in their natural productions the adjacent parts of the 

 continent, almost as much as such widely-separated 

 districts could be expected to do even if they still fornicid 

 a part of Asia ; and this close resemblance, joined with 

 the fact of the wide extent of sea which separates them 

 being so unifonuly and remarkably shallow, and lastly, 

 the existence of the extensive ran^je of volcanoes in 

 Sumatra and Java, which have poured out vast quantities 

 of subtermneau matter and have built up extensive 

 plateaux and lofty mountain ranges, thus furnishing a 

 v€ra caiisa for a paniHel line of subsidence—all lead irre- 

 sistibly to the conclusion that at a very recent geological 

 epoch the continent of Asia extended fiir beyond its 

 present limits in a south-easterly direction, including the 

 islands of Java, Sumatra, and Borneo, and probably reach- 

 ing as far as the present 100-fathom line of soundings. 



The Pliilippine Islands agree in many respects with 

 Asia and the other islands, but present some anomalies, 

 which seem to indicate that they were separated at an 

 earher period, and have since been subject to many 

 revolutions in their physical geography. 



Turning our attention now to the remaining portion of 

 the Archipelago, we shall find that aU the islands from 

 Celebes and Lombock eastward exhibit almost as close a 

 resemblance to Australia and New Guinea as the Western 



