322 NATURE AND MAN. 



the real border of the vast Pacific depression. And as similar 

 features present themseves elsewhere, it may be stated as a general 

 fact that the great continental platfo7'ms usually rise very abruptly 

 from the margins of the real oceanic depressed areas. 



On the other hand, a depression of the existing land of northern 

 Europe to the same or even half that amount would cause very 

 extensive areas of what is now dry land to be overflowed by sea ; 

 the higher tracts and mountainous regions alone remaining as 

 representatives of the continental platform to which the sub- 

 merged portions equally belong. This, as every geologist knows, 

 has been, not once only, but many times, the former condition of 

 Europe ; and finds a singular parallelism in the present condition 

 of that great continental platform of which the peninsula and 

 islands of Malaya are the most elevated portions. For the Yellow 

 Sea, which forms the existing boundary of south-eastern Asia, is 

 everywhere so shallow that an elevation of loo fathoms would 

 convert it into land, while half that elevation would lay dry 

 many of the channels between the Malay Islands, so as to bring 

 them into continuity not only with each other but with the continent 

 of Asia. And Mr. Wallace's admirable researches on the zoology 

 of this region have shown that such continuity undoubtedly existed 

 at no remote period, its mammalian fauna being essentially Asiatic 

 On the other hand, a like elevation would bring Papua into land- 

 continuity with Australia ; with which, in like manner, the intimacy 

 of its zoological relations shows it to have been in former connec- 

 tion. The Indo-Malay province is separated from the Papuo- 

 Australian province by a strait which, though narrow, is so much 

 deeper than the channels which intervene between the separate 

 members of either group that it would still remain as a fissure of 

 considerable depth, even if the elevation of the two parts of the 

 great area it divides were sufficient to raise most of each into dry 

 land. And thus we may view the whole area extending from 

 south-eastern Asia to South Australia as a vast land-platform (partly 

 submerged), of which the great fissure that divides it into two dis- 

 tinct zoological provinces may be considered as corresponding with 

 the great break made by the Mediterranean in the continuity 

 between Europe and Africa, and that made by the Gulf of Mexico 

 and the Caribbean Sea in the continuity between North and 



