428 



ISLAND LIFE. 



[part h. 



species; and we may be sure that at the time when such 

 animals as apes and buffaloes existed, the Asiatic continent 

 swarmed with varied forms of mammals to quite as great an 

 extent as Borneo does now. If the portion of separated land 

 had been anything like as large as Celebes now is, it would 

 certainly have preserved a far more abundant and varied fauna. 

 To explain the facts we have the choice of two theories ; — 

 either that the original island has since its separation been 

 greatly reduced by submersion, so as to lead to the extinction 

 of most of the higher land animals ; or, that it originally formed 

 part of an independent land stretching eastward, and was only 

 united with the Asiatic continent for a short period, or perhaps 

 even never united at all, but so connected by intervening 

 islands separated by narrow straits that a few mammals might 

 find their way across. The latter supposition appears best to 

 explain the facts. The three animals in question are such as 

 might readily pass over narrow straits from island to island; 

 and we are thus better enabled to understand the complete 

 absence of the arboreal monkeys, of the Insectivora, and of the 

 very numerous and varied Carnivora and Ko dents of Borneo, 

 all of which are entirely unrepresented in Celebes by any 

 peculiar and ancient forms except the squirrels. 



The question at issue can only be finally determined by 

 geological investigations. If Celebes has once formed part of 

 Asia, and participated in its rich mammalian fauna which has 

 been since destroyed by submergence, then some remains of 

 this fauna must certainly be preserved in caves or late Tertiary 

 deposits, and proofs of the submergence itself will be found 

 when sought for. If, on the other hand, the existing animals 

 fairly represent those which have ever reached the island, then 

 no such remains will be discovered, and there need be no 

 evidence of any great and extensive subsidence in late Tertiary 

 times. 



Birds of Celebes. — Having thus clearly placed before us the 

 problem presented by the mammalian fauna of Celebes, we 

 may proceed to see what additional evidence is afforded by 

 the birds, and any other groups of which we have sufiicieDt 

 information. About 164 species of true land-birds are now 



