It is often no easy matter to form conclusions with regard to the habits of extinct animals; and too much reliance must not be placed on arguments derived from the habits of their living descendants or their near relations. The older geologists fell into this mistake with regard to the Mammoth, as did even Cuvier. Modern elephants are at present restricted to regions where trees flourish with perennial foliage, and, therefore, it was argued that there must have been a change of climate--either gradual or sudden, in the country of the Mammoth. Cuvier, who believed in sudden revolutions on the earth's surface, argued that the Mammoth could not possibly have lived in Siberia as it is now; and that, at the very moment when the beast was destroyed, the land was suddenly converted into a glacial region! ("C'est donc le même instant qui a fait périr les animaux, et qui a rendu glacial le pays qu'ils habitaient, cet événement a été subit, instantané, sans aucune gradation."[67]) Sir Charles Lyell argued, from geological evidence with regard to the rise of land along the Siberian coast, that the climate had become somewhat more severe, and that finally the Mammoth, though protected by its shaggy coat, died out on account of scarcity of food.[68] [67] _Ossemens Fossiles_, tom. i. p. 108. [68] See _The Principles of Geology_, vol. i. chap. x. Professor Owen is unwilling to believe that such changes as these brought about the final extinction of the Mammoth, and he concludes that it was quite possible for such an animal to have flourished as near to the North Pole as is compatible with the growth of hardy trees or shrubs. "The fact seems to have been generally overlooked, that an animal organised to gain its subsistence from the branches or woody fibre of trees, is thereby rendered independent of the seasons which regulate the development of leaves and fruit; the forest food of such a species becomes as perennial as the lichens that flourish beneath the winter snows of Lapland; and, were such a quadruped to be clothed, like the reindeer, with a natural garment capable of resisting the rigours of an arctic winter, its adaptation for such a climate would be complete.... The wonderful and unlooked-for discovery of an entire Mammoth, demonstrating the arctic character of its natural clothing, has, however, confirmed the deductions which might have been legitimately founded upon the localities of its most abundant remains, as well as upon the structure of its teeth, viz. that, like the Reindeer and Musk Ox of the present day, it was capable of existing in high northern latitudes."[69] [69] _A History of British Fossil Mammals and Birds_, by Richard Owen, F.R.S., etc. London, 1846.