CH. VIII CHABACTEBI8TICS OF SANGIB ISLANDS 189 



' Challenger ' in the Sea of Celebes, about thirty miles west 

 of Siauw. The fact that in the passage the sea was in places 

 as shallow as 232 fathoms, and that nothing deeper than 

 930 fathoms was found, whilst in the open sea the lead went 

 down to the enormous depth of 2,150 fathoms, suggests that 

 when these seas have been more thoroughly surveyed it 

 will be found that there is a continuous submarine range 

 running between Mindanao and Minahassa, which appears 

 above water as the Sangir and Siauw chain of islands. 



It is, however, by no means necessary to assume that 

 there was at any time any land communication between 

 Celebes and the Philippines. To obtain complete land com- 

 munication between the two we should require an eleva- 

 tion of at least 6,000 feet, or in other words, if we believe 

 that Celebes and the Philippines were at one time con- 

 nected by dry land, we must presume that the land has 

 sunk at least 6,000 feet — a presumption we are not justified 

 in making, especially in a volcanic region, without some 

 very good reason. The fauna and flora of the two islands 

 do not afford us evidence sufficiently weighty to justify 

 any such theory. If we found any striking correspondence 

 between the heavy ground-feeding mammals of the two 

 islands we might think differently, but we do not. The 

 babirusa and sapiutan (31 and 70) of Celebes are not known 

 to occur in the Philippines, nor is the Cervus hippelephas, 

 whilst on the other hand there is no true cat, porcupine, 

 shrew, or tragulus in Celebes. 



The fact that many of the squirrels, rats, and bats are 

 identical or very similar in the two islands is not to be 

 wondered at, for /th^se could easily be drifted across the 

 narrow straits separating the links in the chain of connecting 

 islands on drifting timber. 



The opportunities afforded to arboreal animals to migrate 

 from one island to another in these regions are not so in- 



