358 THE ORIGIN OF SPECIES 



fest 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 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 elsewhere 

 include only herbaceous species; now trees, as Alph. de CandoUe 

 has shown, generally have, whatever the cause may be, confined 

 ranges. Hence trees would be little likely to reach distant oceanic 

 islands; and an herbaceous plant, which had no chance of suc- 

 cessfully competing with the many fully developed trees growing 

 on a continent, might, when established on an island, gain an 

 advantage over other herbaceous plants by growing taller and 

 taller and over-topping them. In this case, natural selection would 

 tend to add to the stature of the plant, to whatever order it be- 

 longed, and thus first convert it into a bush and then into a tree. 



ABSENCE OF BATRACHIANS AND TERRESTRIAL MAMMALS ON 

 OCEANIC ISLANDS 



With respect to the absence of whole orders of animals on 

 oceanic islands, Bory St. Vincent long ago remarked that Ba- 

 trachians (frogs, toads, newts) are never found on any of the 

 many islands with which the great oceans are studded. I have 

 taken pains to verify this assertion, and have found it true, with 

 the exception of New Zealand, New Caledonia, the Andaman 

 Islands, and perhaps the Solomon Islands and the Seychelles. But 

 I have already remarked that it is doubtful whether New Zealan4 

 and New Caledonia ought to be classed as oceanic islands; and 

 this is still more doubtful with respect to the Andaman and 

 Solomon groups and the Seychelles. This general absence of frogs, 

 toads, and newts on so many true oceanic islands cannot be ac- 

 counted for by their physical conditions: indeed, it seems that 

 islands 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 immediately 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 islands. 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 carefully 



