OCEANIC ISLANDS. 1 93 



except three are American birds, and most of them 

 are known to be driven to the islands every few 

 years by storms. These islands are, therefore, of 

 the class most readily visited from the continents, 

 and the fauna and flora are in exact accordance with 

 this fact, consisting almost entirely of continental 

 species which can readily cross the water. There 

 are no mammals except bats and rats. And, indeed, 

 mammals are always absent from oceanic islands, 

 appearing to have no power of crossing large bodies 

 of water. There are no frogs ; and these animals 

 also have no power to pass bodies of salt water. 

 There are no snakes, but one single lizard is found, 

 which is the only remarkable animal on the islands. 

 It is a peculiar species, and strange to say is consid- 

 ered by Goode to have its nearest allies in Africa. 

 There are one hundred and sixty-eight species of 

 birds, all but three being American species which 

 have crossed the water. The other three are Euro- 

 pean species which have been introduced from 

 Europe. Insects are scarce, but all are either North 

 American or West Indian species. Of land Mol- 

 lusca there are twenty species, four of which are 

 considered peculiar to the islands. Of the seven 

 hundred and twenty species. of plants five hundred 

 and seventy have been introduced since the advent 

 of man. One hundred and fifty were native island 

 species, and are either North American or West 

 Indian plants. It is doubtful whether a single 

 species of plant really deserves to be called a pe- 

 culiar species, although there are some half a dozen 

 which may possibly be so ranked. The whole 



