"Were one to consult only reason and analogy, such assertions would appear to be doubtful, as a matter of experience they are found to be absolutely false. Let any one glance at the evidence upon which these pretended identities rest; one will then see that they exist only in the names, and that there is not a single WELL-KNOWN animal belonging to the northern hemisphere, which is not specifically different from all other animals EQUALLY WELL KNOWN in the opposite hemisphere. I have taken the trouble to make that difficult comparison in the case of the cetacea, the seals, etc.; I have examined many histories of voyages; I have gathered together all the descriptions of animals; and I have recognised important differences between the most similar of these supposedly identical species. "Nobody, I dare say, has collected more animals than I have done in the southern hemisphere. I have observed and described them in their own habitat. I have brought several thousands of kinds to Europe; they are deposited in the Natural History Museum at Paris. Let any one compare these numerous animals with those of our hemisphere, and the problem will soon be resolved, not only in regard to the more perfectly organised species, but even as to those which are simpler in structure, and which, in that regard, it would appear, should show less variety in nature...In all that multitude of animals from the southern hemisphere, one will observe that there is not one which can be precisely matched in northern seas; and one will be forced to conclude from such a reflective examination--such an elaborate and prolonged comparison--as I have been forced to do myself, THAT THERE IS NOT A SINGLE SPECIES OF WELL-KNOWN ANIMALS WHICH, TRULY COSMOPOLITE, IS INDISTINGUISHABLY COMMON TO ALL PARTS OF THE GLOBE. "More than that--and it is in this respect above all that the inexhaustible variety of nature shines forth--however imperfect each of these animals may be, each has received its own distinct features. It is to certain localities that they are fixed; it is there that they are found to be most numerous, largest in size and most beautiful; and to the extent that they are found most distant from the appropriate place, the individuals degenerate and the species becomes gradually extinguished."