BY N. DE MIKLOUHO-MACLAY 967 



Bongu, are followed by many others, as layers of small boulders 

 and marine detritus of different kinds (mostly coral fragments), 

 imbedded in other layers of clay, and all covered over with a 

 stratum of dark-brown humus of variable thickness, which is the 

 ground for a luxuriant, tropical primeval forest, where trees many 

 centuries old are not uncommon. 



Besides the above mentioned layers at different levels above the 

 sea, I have seen large blocks of corals (mostly of the genera, 

 Meandrina and Astraea), in some isolated spots, where the dense 

 vegetation and the cover of humus has been removed (by 

 man, or accidentally), and the deeper layers of soil, under the 

 humus, left bare. I have noticed such blocks in and near villages 

 many hundred feet above the sea. Once I obtained a piece of 

 coral [Prionastraea, spec. ^) amongst small stone in the bed of the 

 river Koli, near Sangdinbi-Mana, not less than 1,200 feet above 

 the level of the sea, and from all appearance the piece was brought 

 down by water (1) from some place higher up. (2.) Another 

 proof that the coast is still rising is the existence of numerous reefs 

 of dead corals which are left quite diy at each low tide. 



Considering the facts, that the elevation of the raised coral reefs 

 on different portions of the Maclay-Coast, as well as on the Islands 

 of the Archipelago of contented men, presents the same level above 

 the sea, and like the layers of the greenish clay are, as far as I have 

 observed, horizontal, it appears to me not unlikely, that besides 

 the occasional upheavals, there exists a gradual steady rising of 

 this part of the North-Eastern Coast of New Guinea. 



(1.) Some rivers of the Maclay-Coast as for instance the river Koli 

 presents during the dry season, but a narrow band of running water in a 

 very large bed filled with stones of all dimensions and some bands of sand. 

 After heavy rains in the mountains the water rushes with great velocity 

 bringing down more stones and trees, which are left behind in the bed of the 

 river when the water falls to wait for the next rain and the next flood. 



(2.) I confess, that the finding of a loose piece of coral cannot be regarded 

 as a decided proof of the origin of the same, from a coral bank raised to over 

 1000 feet. It might have happened (which however is not very likely,) that 

 the piece of coral has been brought there and dropped by some passing 

 native. 



