Nevertheless the simplicity of the view that each species was first produced within a single region captivates the mind.

He who rejects it, rejects the vera causa of ordinary generation with subsequent migration, and calls in the agency of a miracle.

It is universally admitted, that in most cases the area inhabited by a species is continuous; and that when a plant or animal inhabits two points so distant from each other, or with an interval of such a nature, that the space could not have been easily passed over by migration, the fact is given as something remarkable and exceptional.