And the completely worthless character of such "evidence" of age becomes, if possible, more apparent when we consider that very many of these so-called "extinct" forms are not really distinct species from their living representatives of to-day. "It is notorious," says Darwin, "on what excessively slight differences many palaeontologists have founded their species." And even to-day, in spite of all that we have learned about variation, little or no allowance seems ever to be made for the effects of a certainly greatly changed environment. If the fossil forms among the mollusks and other shell fish for instance, are not precisely like the modern ones in every respect, they are always classed as separate species, the older forms thus being "extinct," in utter disregard of the striking anatomical differences between the huge Pleistocene mammals and their dwarfish descendants of to-day, which for a hundred years or so were declared positively to be distinct from one another, but are now acknowledged to be identical. Of course no one denies that there are numerous extinct forms among the invertebrates, just as we know there are among the huge vertebrates of the Mesozoic and Tertiaries, none of which we moderns have ever seen alive. Other forms do not appear familiar to our modern eyes, because larger or of somewhat different form; but to say that they are really distinct species from their modern representatives, or to say that no human being ever saw them alive, are statements utterly incapable of proof. Up to about the year 1869 it was stoutly maintained that man had never seen =any= of these fossil forms in life. But no one now maintains this view, for human remains have now been found along with undisturbed fossils of the Pleistocene, or even middle Tertiaries, while the paintings on the cave walls of Southern France seem conclusive that they were copied from life when the mammoth and reindeer lived side by side with man in that latitude. Hence the only question now is, and it is the supreme question of all modern geology, =WITH HOW MUCH OF THAT ANCIENT FOSSIL WORLD WERE THESE EQUALLY FOSSIL MEN ACQUAINTED?= If Man lived in "Pliocene" or perhaps "Miocene times," when a luxuriant vegetation was spread out over all the Arctic regions, what possible evidence is there to show that his companions, the rhinoceros, hippopotamus, mammoth, etc., were not also living then and browsing off just such plants, when the Arctic frosts caught them in the grip of death and put their "mummies" in cold storage for our astonishment and scientific information? Things which are equal to the same thing are equal to each other; why should not the plants and animals, contemporary with the same creature (man), be just as truly contemporary with one another? If man was contemporary with the Miocene plants, and the Pleistocene mammals were contemporary with man, what is there to forbid the idea that the