and formed the real stock of the Drift fauna, as described by Von Zittel in his “Palæozoology.” [Illustration: AN ACTUAL PHOTOGRAPH OF THE PREHISTORIC MAMMOTH This stuffed carcase of a mammoth is the rarest treasure of St. Petersburg Academy. Skeletons of these creatures exist in plenty, but actual carcases are very rare. This was found embedded in the ice on the New Siberian Islands. One carcase so embedded was discovered five years before it could be freed from the ice. ] One thing is certain--namely, that the northern borders of Siberia were not the real home of the mammoth and its companions; the original habitat of these animals points to the far interior of Asia, particularly to the wild table-lands, where they so far steeled themselves in enduring the climate that in the course of the Glacial Period half the world became accessible to them. As far as is known to-day, the mammoth arrived in Europe earlier than on the northern borders of Asia, where, protected by climatic conditions, its remains are most numerous and best preserved. The number of these gigantic animals must have been very considerable in this Far Northern region for a time, judging from the abundance of bones found there. In Central Europe only a few places are known--such as Kannstatt, Predmost in Moravia, etc.--where the mammoth is found with similar frequency. The mammoth attained its widest distribution in the Interglacial Period. In that period it crossed the Alps, and arrived on the other side, in North Asia, at the border of the “stone-ice” masses of inland ice that were still preserved from the first Glacial Period. The vegetation there was richer then than it is to-day; now only the vegetation of the tundra can exist. Animals found coniferæ, willows, and alders in sufficient quantity to enable them to keep in herds. All the same, we have not to imagine the climate on the borders of the ice to have been “genial,” for from that period originate the mammoth carcases that are found frozen entire in crevasses of the ice-fields. When the new period of cold--the second Glacial Period--began, these Far Northern regions must have become unsuitable for the mammoth owing to the want of food. Von Toll, who has examined the fossil ice-beds and, their relation to the mammoth carcases particularly on New Siberian Islands, says: The mammoths and their contemporaries lived where their remains are found; they died out gradually in consequence of physical geographical changes in the region they inhabited, and through no catastrophe; their carcases were deposited during low temperatures, partly on the river-terraces, and partly on the banks of lakes or on glaciers (inland ice), and covered with mud; like the ice-masses that formed the foundation of their graves, their mummies were preserved to the present day, thanks to the persistent or increasing cold. [Illustration: SKELETON OF A MAMMOTH