Introduction: Wallace’s line. 
S9 
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 adopting 
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 wRere 
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. 315 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 Sun dan, 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 & Wi glesw o r th, Birds of Celebes (May 5tli, 1808). 
72 
