CHAP. XX CELEBES 457 



Frohahle Derivation of the Mammals of Celebes. — It is 

 clear that we have here a group of extremely peculiar, and, 

 in all probability, very ancient forms, which have been 

 preserved to us by isolation in Celebes, just as the mono- 

 tremes and marsupials have been preserved in Australia, 

 and so many of the lemurs and Insectivora in Madagascar. 

 And this compels us to look upon the existing island as a 

 fragment of some ancient land, once perhaps forming part 

 of the great northern continent, but separated from it far 

 earlier than Borneo, Sumatra, and Java. The exceeding 

 scantiness of the mammalian fauna, however, remains to 

 be accounted for. We have seen that Formosa, a much 

 smaller island, contains more than twice as many 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 Rodents of 

 Borneo, all of which except the squirrels are entirely un- 

 represented in Celebes by any peculiar and ancient forms. 



The question at issue can only be finally determmed by 

 geolosfical investig^ations. If Celebes has once formed part 

 of Asia, and participated in its rich mammalian launa, 

 which has been since destroyed by submergence, then some 



