Introduction: Wallace's line. SI 



restrict ourselves to the ornithological facts at our disposal, taking the Avifauna 

 of Celebes as the basis for this purpose. Conclusions which may be drawn from 

 ornithological facts alone must, however, be weighed very carefully, as birds 

 have their own modes of dispersal. We shall then see in how far these con- 

 clusions differ from those arrived at by other means. 



Wallace's line. 



As is generally known Mr. Wallace drew a line to the west of Celebes 

 by which the Archipelago was divided into two widely ditfering halves. This 

 division was welcomed with much approbation on account of the fascinatino' 

 speculations of its inventor, though these speculations were more suggestive 

 than substantially founded upon and backed by facts, some of which were not 

 taken into consideration, and others were not available with oui- defective know- 

 ledge of 20 or 30 years ago, nor indeed are they available to-day. 



Mr. Wallace has, however, in the course of his later studies modified his 

 views in some respects. At first, as in the "Malay Archipelago" (1869) and in 

 the "Geographical Distribution of Animals" (1876) — not to mention earlier 

 writings') — the line passes between BaU and Lombok, through the Macassar 

 Strait west of Celebes, turning to the east between Mindanao and Halmahera; 

 while he adds in "Island Life" (1880, 431) "that the present land of Celebes 

 has never (in Tertiary times been united to the Asiatic continent, but has re- 

 ceived its population of Asiatic forms by migration across narrow straits and 

 intervening islands". He draws in the latter work (p. 434) the following con- 

 clusion: "We have in this island a fragment of the great eastern continent 

 which has preserved to us, perhaps from Miocene times, some remnants of its 

 ancient animal forms"; and (p. 509): "I now look upon Celebes as an outlying 

 portion of the great Asiatic continent of Miocene times, which either by sub- 

 mergence or some other cause had lost the greater portion of its animal inhabi- 

 tants and since then has remained more or less completely isolated from every 

 other land. It has thus preserved a fragment of a veiy ancient fauna along 

 with a number of later types which have reached it from surrounding islands 

 by the ordinary means of dispersal". He further says in his "Australasia" fed. 

 by Dr. Guillemard 1894, p. 287): "The peculiarities of the animal life of 

 Celebes may be best explained by supposing it to be an outlying portion of 

 that Miocene continent, which became detached from it, and has since never 

 been actually joined to any Asiatic or Australian land. It has thus preserved 

 to us some descendants of ancient types, and these have become intermingled 

 with such .immigrants from both east and west as were enabled to establish 



Florenreiclie der Erde, Petermann's Erg. Heft Nr. 74 1884, Atlas der Pflanzenverbreitung I8S7, Haudbuch der 

 Pflanzengeographie 1890. Warburg (Die Flora des asiatischen Monsungebietes : Verb. Ges. Deutscher Naturf. 

 AUg. TheU 1890, especially concerning South Celebes^ etc. 



1) These earlier -n-ritings are to be found in the Ibis 18.i9, 450; J. of the Proc. Linn. Soc, Zool., I860, 

 R^ 172; P. Z. S. 1863, 481; J. R. Geogr. Soc, 1863. XXXIH, 217; Edinburgh PhUos. .loum., new ser.. 1864, 

 XIX, Nr. 1, etc. 



M e y e r & W i g 1 c s w r t h , Birds of Celebes i Jlay .'ith. 1898). ' ' 



