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 Candolle has shown, generally have, whatever the cause may be, confined ranges.