192 THE ORIGIN OF SPECIES 



that islauils are peculiarly fitted for these animals; for 

 frogs have been introduced into Madeira, the Azores, 

 and Mauritius, and have multiplied so as to become a 

 nuisance. But as these animals and their spawn are im- 

 mediately killed (with the exception, as far as known, 

 of one Indian species) by sea-water, there would be great 

 difficulty in their transportal across the sea, and therefore 

 we can see why they do not exist on strictly oceanic isl- 

 ands. But why, on the theory of creation, they should 

 not have been created there, it would be very difficult 

 to explain. 



Mammals offer another and similar case. I have care- 

 fully searched the oldest voyages, and have not found a 

 single instance, free from doubt, of a terrestrial mammal 

 (excluding domesticated animals kept by the natives) in- 

 habiting an island situated above 300 miles from a con- j 

 tinent or great continental island; and many islands sit- 

 uated at a much less distance are equally barren. The 

 Falkland Islands, which are inhabited by a wolf-like fox, 

 come nearest to an exception; but this group cannot be , 

 considered as oceanic, as it lies on a bank in connection \ 

 with the mainland at the distance of about 280 miles; j 

 moreover, icebergs formerly brought bowlders to its west- I 

 ern shores, and they may have formerly transported 

 foxes, as now frequently happens in the arctic regions. | 

 Yet it cannot be said that small islands will not support j 

 at least small mammals, for they occur in many parts of 

 the world on very small islands, when lying close to a 

 continent; and hardly an island can be named on which 

 our smaller quadrupeds have not become naturalized and 

 greatly multiplied. It cannot be said, on the ordinary * 

 view of creation, that there has not been time for the 



