174 MB. A. B. WALLACE OK THE ZOOLOGICAL 



(only ] 5 miles wide) marks the limits and abruptly separates two 

 of the great Zoological regions of the globe. The Philippine 

 Islands are in some respects of doubtful location, resembling and 

 differing from both regions. They are deficient in the varied 

 Mammals of Borneo, but they contain no Marsupials. The Psittaci 

 are scarce, as in the Indian region ; the Lories are altogether ab- 

 sent, but there is one representative of the Cockatoos. Woodpeckers, 

 Trogons, and the genera Ixos, Copsychus, and JPloeeus are highly 

 characteristic of India, Tanysiptera and Megapodius, again, are 

 Australian forms, but these seem represented by only solitary 

 species. The islands possess also a few peculiar genera. "We 

 must on the whole place the Philippine Islands in the Indian region, 

 but with the remark that they are deficient in some of its most 

 striking features. They possess several isolated forms of the Au- 

 stralian region, but by no means sufficient to constitute a real 

 transition thereto. 



Leaving the Philippines out of the question for the present, the 

 Avestern and eastern islands of the Archipelago, as here divided, 

 belong to regions more distinct and contrasted than any other of the 

 great zoological divisions of the globe. South America and Africa, 

 separated by the Atlantic, do not differ so widely as Asia and 

 Australia : Asia with its abundance and variety of large Mammals 

 and no Marsupials, and Australia with scarcely anything but 

 Marsupials ; Asia with its gorgeous Phasianidce, Australia with 

 its didl-coloured MegapodiidcB ; Asia the poorest tropical region 

 in Parrots, Australia the richest : and all these striking charac- 

 teristics are almost unimpaired at the very limits of their respective 

 districts ; so that in a few hours we may experience an amount of 

 zoological difference which only weeks or even months of travel 

 will give us in any other part of the world ! 



Moreover there is nothing in the aspect or physical character of 

 the islands to lead us to expect such a difference ; their physical 

 and geological differences do not coincide with the zoological 

 differences. There is a striking homogeneity in the two halves 

 of the Archipelago. The great volcanic chain runs through both 

 parts ; Borneo is the counterpart of New Gruinea ; the Philip- 

 pines closely resemble the equally fertile and equally volcanic 

 Moluccas ; while in eastern Java begins to be felt tlie more arid 

 climate of Timor and Australia. But these resemblances are 

 accompanied by an extreme zoological diversity, the Asiatic and 

 Australian regions finding in Borneo and New Gruinea respectively 

 their highest development. 



