Chap. XIII.] INHABITANTS OF OCEANIC ISLANDS. 181 



other classes ; thus in the Galapagos Islands reptiles, 

 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 profoundly 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 

 appurtenances 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 

 differences 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 conditions. 



Many remarkable little facts could be given with 

 respect to the inhabitants of oceanic islands. For 

 instance, in certain islands not tenanted by a single 

 mammal, 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 mio-ht 

 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 

 appendage like the shrivelled wings under the soldered 

 wing-covers of many insular beetles. Again, islands 

 often possess trees or bushes belonging to orders which 



