Introduction: Wallace's line. gQ 



specialists of the highest standing acquiesce in the line, partly disregarding the 

 circumstance that Wallace himself has to a certain degree altered his views; 

 whereas others of the same rank encounter insuperable obstacles in adoptino- 

 such a frontier between the Oriental and Australian Regions. There can be 

 no doubt that in our present state of knowledge it is premature to define the 

 problem for solution, however interesting and suggestive it may be, and that it 

 is, therefore, waste of time to speculate on it with the help of an up-and-down 

 system for the islands and continents, just as required. It is characteristic of 

 an inadequate hypothesis that it is always in need of a new one which should 

 sustain it, and as geology and palaeontology are as yet powerless to guide us, 

 we must restrict ourselves to zoology, though we know that here also our 

 knowledge is defective in a high degree. Let us see, however, what the orni- 

 thology of Celebes in its present state teaches, and whether our results agree 

 at least with those arrived at by others. 



What are the characteristic elements of the Celebesian Avifauna and where 

 did they originate? This is the only question we put, and which we will try 

 to answer — always bearing in mind that our ornithological knowledge of Celebes, 

 especially of the centre and high mountains, is imperfect — , leaving all further 

 speculations to the naturalist of the future. 



The following table of the Geographical Distribution of the species treated 

 of in this book will facilitate the answer to our question. It will be observed 

 that the Celebesian Area is flanked to the left by the Nearctic, Ethiopian, 

 Palaearctic and Oriental Regions, to the right by the Australian and Neotropical 

 Regions, the generally adopted Sclaterian division having been accepted for 

 convenience's sake, though we are aware that that of Prof. Newton ^D. B. 1893, 

 p. 3ib et seq.) is an improvement upon it. (His main divisions are the New 

 Zealand, Australian, Neotropical, Holarctic, Ethiopian and Indian Regions; unit- 

 ing under the Holarctic the Nearctic and Palaearctic, and separating the former 

 Australasian Region into an Australian and a New Zealand Region.) The affinities 

 of the Celebesian Avifauna make it preferable to break up the Oriental Region 

 into several parts, inserting between them Japan — a section of the Palaearctic 

 Region, as follows: Indian Province, Chinese Province, Japan, the Malay Pen- 

 insula, Sumatra, Java, and Borneo. For similar reasons we have divided the 

 Australian Region into Papuasia, Australia, Polynesia, and New Zealand. As 

 to the middle parts of the East Indian Archipelago we advocate, as will be seen 

 later on, the recognition of a broad Transition-Zone, comprising four areas — 

 a Philippine, a Celebesian, a Lesser Sundan, and a Moluccan, — although the 

 three first display a preponderance of Asiatic elements, while the Moluccas 

 correspond naturally to their geographical position between Sula and Papuasia. 



Meyer & Wiglesworth, Birds of Celebes (May 5iii, IS'JS). fj 



