There is a popular idea that pigs cannot swim, but Sir Charles Lyell has shown that this is a mistake.

In his "Principles of Geology" (10th Edit.

vol.ii p.

355) he adduces evidence to show that pigs have swum many miles at sea, and are able to swim with great ease and swiftness.

I have myself seen a wild pig swimming across the arm of the sea that separates Singapore from the Peninsula of Malacca, and we thus have explained the curious fact, that of all the large mammals of the Indian region, pigs alone extend beyond the Moluccas and as far as New Guinea, although it is somewhat curious that they have not found their way to Australia.
The little shrew, Sorex myosurus, which is common in Sumatra, Borneo, and Java, is also found in the larger islands of the Moluccas, to which it may have been accidentally conveyed in native praus.
This completes the list of the placental mammals which are so characteristic of the Indian region; and we see that, with the single exception of the pig, all may very probably have been introduced by man, since all except the pig are of species identical with those now abounding in the great Malay islands, or in Celebes.
The four remaining mammals are Marsupials, an order of the class Mammalia, which is very characteristic of the Australian fauna; and these are probably true natives of the Moluccas, since they are either of peculiar species, or if found elsewhere are natives only of New Guinea or North Australia.