raised sufficiently to unite all the islands on

each side of the deep water into two great

tracts of land, separated

the deep strait of water.

from one another by

Each of these great

tracts of land would then have had their own distinctive kinds of quadrupeds—just as the American quadrupeds are now distinct from the European; for the comparatively narrow strait between the then Malay continents would have offered as effectual a barrier to the migration of quadrupeds as does the Atlantic Ocean at the present day. Hence, when all the land slowly subsided so as to leave only its mountain chains. and table lands standing above the surface in the form of islands, we now have the state of things which Mr. Wallace describes-viz., two large groups of islands with the quadrupeds on the one group differing widely from the quadrupeds on the other, while the other, while within the limits. of the same group the quadrupeds inhabiting

different islands all belong to the same or to closely allied species. On this highly interesting subject Darwin writes, "I have not as yet had time to follow up this subject in all quarters of the globe; but as far as I have gone the relation holds good. For instance, Britain is separated by a shallow channel from Europe, and the mammals are the same on both sides, and so it is with all the islands near the shores of America. The West Indian islands, on the other hand, stand on a deeply submerged bank nearly 1,000 fathoms in depth, and here we find American forms, but the species, and even the genera, are distinct. As the amount of modification which animals of all kinds undergo partly depends on lapse of time, and as the islands which are separated from each other or from the mainland by shallow channels are more likely to have been continuously united within a recent period than the islands separated by

deeper channels, we can understand how it is that a relation exists between the depth of the sea separating two mammalian faunas, and the degree of their affinity—a relation which is quite inexplicable on the theory of independent acts of creation."

So much, then, for the argument from geographical distribution-the many facts of crucial importance which it affords almost resembling so many experiments devised by Nature to prove the falsity of the special creation hypothesis. For now,

let it in conclusion be observed, that there is no physiological reason why animals and plants of the different characters observed should inhabit different continents, islands, seas, and so forth. As Darwin observes, "there is hardly a climate or condition in the Old World which cannot be paralleled in the New

and yet how

widely different are their living productions.”

And that it is not the suitability of organisms

to the areas which they inhabit which has determined their creation upon those areas, is conclusively proved by the effects of the artificial transportation of species by man. For in such cases it frequently happens that the imported species thrives quite as well in its new as in its old home, and indeed often supplants the native species. As the Maoris say," As the white man's rat has driven away the native rat, so the European fly has driven away our fly, so the clover kills our fern, and SO will the Maori himself disappear before the white man."

Upon the whole then we are driven to the conclusion, that if the special creation theory is true, the various plants and animals have not been placed in the various habitats which they occupy with any reference to the suitability of these habitats to the organisations of these particular plants and animals.

So

that, considering all the evidence under the head of geographical distribution, I think we are driven to the yet further conclusion, that if the special creation theory is true, the only principle which appears to have been consistently followed in the geographical deposition of species, is the principle of so depositing them as in all cases to make it appear that the supposition of their having been thus deposited is not merely a highly dubious one, but one which,

on the face of it, is conspicuously absurd.