132 Prof. Dr. Max Weber on the 



words '' we must conclude that the whole of this area (the 

 tropical Pacific region) has remained geologically isolated from 

 the other regions of this zone since the commencement of the 

 existence of Teleostei." As a zoologist one will readily agree 

 with the view of this distinguished ichthyologist that Australia 

 was at one time separated from Asia, when the Teleostei first 

 appeared, so that only one of the oldest types — Osteoglossum 

 — could occur there and in the Malay Archipelago. But for 

 Celebes, according to the present state of our knowledge, 

 such an explanation no longer seems to be correct. 



The separation of Celebes from the Asiatic continent can 

 only have taken place after the immigration of Anoa depressi- 

 corm'Sf Dabirussa alfurus, Cynopithecus nige)',Macacusmaurus, 

 ParadoxuruSj Sciurus, Tarsi'us, and other Indian forms. 

 Even if the preservation of single species among these {Anoa, 

 Bahi'russa, Cynopithecus, Macacus maurus) as solitary specimens 

 in Celebes is taken as a sign of their great age, they still 

 cannot be older than Siluridte and Cyprinida3. If, notwith- 

 standing, the Indian river-fishes did not take part in the 

 immigration of the Indian mammals, then it was probably 

 because the hydrographical condition did not favour such 

 immigration. It must also be remembered that in those early 

 Tertiary times Cyprinidse and Siluridse had not yet such a 

 wealth of species as has since been developed. 



We grant therefore to Celebes a longer connexion with 

 the Asiatic continent than was allotted to Australia. The 

 poverty in freshwater fishes in Australia and Celebes has a 

 difierent cause. Australia was separated from the Asiatic 

 continent as far back as the first appearance of Teleostei ; 

 Celebes, on the other hand, was separated later, when 

 Cyprinidse and Siluridaj had already appeared, though still 

 sparingly. In consequence of its splitting up into small 

 islands it did not, however, offer the hydrographical con- 

 ditions necessary for the reception and development of a fresh- 

 water fauna. 



If my investigations have become more and more concen- 

 trated on Celebes, this has arisen because the fauna of Celebes 

 has already been so often a subject of discussion, and because 

 Celebes is in many respects a prototype of the other eastern 

 islands. This does not mean that the conditions are exactly 

 the same for Flores, Timor, and Amboina as for Celebes. On 

 the contrary, the age of these islands is entirely different, as 

 also their fauna ; but for the fish-fauna of the above-named 

 islands the same conditions obtain, except that Celebes has 

 always the advantage of a greater area of fresh water. 



As regards the fish-fauna, we came to the conclusion that 



