As an example, four species of the Papilionidae 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 Pieridae (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 in 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 positive evidence that such has been the mode of peopling the islands.

Their productions are of that miscellaneous character 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 render it quite impossible to explain those curious relations which the best known group of animals (the birds) have been shown to exhibit.