chap, xiv.] OF THE TIMOR GROUP. 329 



Birds have many peculiar species, with a decided relation- 

 ship to those of the two nearest masses of land. The 

 insects have similar relations with the birds. As an ex- 

 ample, four species of the Papilionidse are peculiar to 

 Timor, three others are also found in Java, and one in 

 Australia. Of the four peculiar species two are decided 

 modifications of Javanese forms, while the others seem 

 allied to those of the Moluccas and Celebes. The very few 

 land shells known are all, curiously enough, allied to or 

 identical with Moluccan or Celebes forms. The Pieridfe 

 (white and yellow butterflies) which wander more, and 

 from frequenting open grounds are more liable to be blown 

 out to sea, seem about equally related to those of Java, 

 Australia, and the Moluccas. 



It has been objected to Mr. Darwin's theory, — of Oceanic 

 Islands having never been connected with the mainland, — 

 that this would imply that their animal population was a 

 matter of chance ; it has been termed the "flotsam and 

 jetsam theory," and it has been maintained that nature 

 does not work by the " chapter of accidents." But in the 

 case which I have here described, we have the most posi- 

 tive evidence that such lias been the mode of peopling the 

 islands. Their productions are of that miscellaneous cha- 

 racter which we should expect from such an origin ; and 

 to suppose that they have been portions of Australia or of 

 Java will introduce perfectly gratuitous difficulties, and 



