The Malay archipelago : the land of the orang-utan ... - Wallace Online

8 THE MALAY ARCHIPELAGO. [chap.Austro-Malayan divisions of tlie Ai'chipelago. (See PliysicalMap.)In Mr. Earl's pamphlet, however, he argues in favour of theformer land-connexion of Asia and Australia, whereas itappears to me that the evidence, taken as a whole, points totheir long- continued sepai'ation. Notwithstanding this andother important differences between us, to him undoubtedlybelongs the merit of first indicating the division of the Archipelagointo an Australian and an Asiatic region, which ithas been my good fortune to establish by more detailedobservations.Contrasts in Natural Productions.—To understand the importanceof this class of facts, and its bearing upon the former distributionof land and sea, it is necessary to consider the results arrived atby geologists and naturalists in other parts of the world.It is now genei-ally admitted that the pi'esent distribution ofliving things on the surface of the earth is mainly the result ofthe last series of changes that it has undergone. Geology teachesus that the surface of the land and the distribution of land andwater is everywhere slowly changing. It further teaclies us thatthe forms of life which inhabit that surface have, during everyperiod of which we possess any record, been also slowly changing.It is not now necessary to say anj^thing about hoio either ofthose changes took place ;as to that, opinions may differ : butas to the fact that the changes themselves have occurred, fromthe earliest geological ages down to the present day, and arestill going on, there is no difference of opinion. Every successivestratum of sedimentary I'ock, sand, or gravel, is a proof thatchanges of level have taken i^lace ; and the different species ofanimals and plants, whose remains are found in these deposits,prove that corresponding changes did occur in the organicworld.Taking, therefore, these two series of changes for granted, mostof the present peculiarities and anomalies in the distribution ofspecies may be directly traced to them. In our own islands, witha very few trifling exceptions, every quadruped, bird, reptile,insect, and plant, is found also on the adjacent continent. Inthe small islands of Sardinia and Corsica, there are some quadrupedsand insects, and many plants, quite peculiar. In Ceylon,more closely connected to India than Britain is to Europe, manyanimals and plants are diflerent from tliose found in India, andpeculiar to the island. In the Galapagos Islands, almost everyindigenous living thing is peculiar to them, though closely resemblingother Icinds found in the nearest parts of the Americancontinent.Most naturalists now admit that these facts can only be exlilainedby the greater or less lapse of time since the islands wereui)raised from beneath the ocean, or were separated from thenearest land ; and this will be generally (tliougli not always) indicatedby the depth of the intervening sea. The enormous