222 MR. A. H. EVERETT ON THE ZOO-GEOGRAPHFCAL [Apr. l6, 



pines. The significance of such a condition of things in the sub- 

 marine geography of the area between Borneo and the Philippines is 

 too well understood to render it necessary to enlarge upon it here ; 

 and if the settlement of the point at issue depended upon considera- 

 tions of physical geography alone, it would probably be at once 

 conceded by all that to include the Palawan group as an integral 

 part of the Philippine sub-area is to draw a purely arbitrary line of 

 delimitation somewhere through the Balabac straits and to the 

 westward of Cagayan-Sulu and Sibutu, instead of adopting the 

 natural boundary which soundings demonstrate to exist already in the 

 Mindoro and Sibutu straits. 



But the geographical evidence for the connexion here advocated, 

 thovigh valuable in so far as it shows that a very sliglit elevation of 

 the sea-bed would suffice now, and may have sufficed in the past, to 

 join the Palawan group to Borneo, while one of considerable magni- 

 tude would be required to eifect a junction with the Philippines, 

 is not of convincing weight unless it can be shown that it is con- 

 firmed by the characteristic features of the Palawan fauna. For if 

 we were to rely on the argument of physical geography alone, we 

 should be confronted with the fact that Celebes might jnst as well 

 be regarded as having been directly connected in recent geological 

 time with Borneo, since that island also is apparently linked to the 

 latter by a broad band of submarine bank, on which the soundings 

 are everywhere, so far as is ascertained, less than 100 fathoms. And 

 as this argument might be advanced, and this bank in the Straits of 

 Macassar is a real difficulty, in view of the extreme dissimilarity 

 of the faunas on either side of that strait, I may be permitted to 

 digress for a moment before proceeding to examine the Palawan 

 fauna, and to point out that in consequence of local circumstances, 

 which are absent in the case of Palawan, this apparent evidence of 

 a recent land-connexion between Borneo and Celebes is susceptible 

 of being otherwise interpreted. The interpretation has been suggested 

 by Mr. Wallace, who remarks': " The southern portion of the Straits 

 of Macassar is full of coral reefs, and a shallow sea of less than 

 100 fathoms extends from Borneo to within about 40 miles of the 

 western promontory of Celebes; but farther north there is deep 

 water close to the shore, and it seems probable that a deep channel 

 extends quite through the straits, which have no doubt been much 

 shallowed by the deposits from the great Bornean rivers as well as 

 by those of Celebes itself. Southward, again, the chain of volcanic 

 islands from Baly to Timor rise out of a deep ocean, the few soundings 

 we possess showing depths of from 670 to 1300 fathoms almost 

 close to their northern shores. We seem justified therefore in 

 concluding that Celebes is entirely surrounded by a deep sea, which 

 has, however, become partially filled up by river-deposits, by volcanic 

 upheaval, or by coial reefs. Such shallow seas, where they exist, 

 may therefore be due to antiquity and isolation, instead of being 

 indications of a former union with any of the surrounding islands." 

 The rainfall in Borneo is enormous, and the country is largely made 



1 ' Island Life; p. 423. 



