Chap. XUI.] INHABITANTS OF OCEANIC ISLANDS. 181 



and in New Zealand gigantic wingless birds, take, or 

 recently took, the place of mammals. Although New 

 Zealand is here spoken of as an oceanic island, it is in 

 some degree doubtful whether it should be so ranked; 

 it is of large size, and is not separated from Australia 

 by a profoimdly deep sea; from its geological charac- 

 ter and the direction of its mountain-ranges, the Eev. 

 W. B. Clarke has lately maintained that this island, 

 as well as New Caledonia, should be considered as ap- 

 purtenances of Australia. Turning to plants. Dr. 

 Hooker has shown that in the Galapagos Islands the 

 proportional numbers of the different orders are very 

 different from what they are elsewhere. All such dif- 

 ferences in number, and the absence of certain whole 

 groups of animals and plants, are generally accounted 

 for by supposed differences in the physical conditions 

 of the islands; but this explanation is not a little 

 doubtful. Facility of immigration seems to have 

 been fully as important as the nature of the condi- 

 tions. 



Many remarkable little facts could be given with 

 respect to the inhabitants of oceanic islands. For in- 

 stance, in certain islands not tenanted by a single mam- 

 mal, some of the endemic plants have beautifully hooked 

 seeds; yet few relations are more manifest than that 

 hooks serve for the transportal of seeds in the wool or 

 fur of quadrupeds. But a hooked seed might be 

 carried to an island by other means; and the plant then 

 becoming modified would form an endemic species, still 

 retaining its hooks, which would form a useless append- 

 age like the shrivelled wings under the soldered wing- 

 covers of many insular beetles. Again, islands often 

 possess trees or bushes belonging to orders which else- 



