We are not without evidence, also, of a much more severe climate. In a lignite bed (a species of coal) found in nearly the same latitude as the forest growth just mentioned, we detect the presence of trees that grow only in cold northern climates, such as birch, mountain pine, larch, and spruce.18 And in some peat-bogs of Southern Europe belonging to this age19 are found willows now growing only in Spitzbergen, and some species of mosses that only thrive far to the north. It is quite evident that this deposit testifies to an altogether different climate from that indicated by the deposit before mentioned. No theory of migration can explain this assemblage of plants, unless it be migration taking place very slowly, in consequence of an equally slow change of climate. From what we have just learned of the animals and plants living in Europe during this age, we can frame some conception of the different climatic conditions of Europe. On the one hand, we have a country with a mild and genial climate. Trees of a warm latitude were then growing as far north as Paris, and we may well suppose Europe to have abounded in shady forests and grassy plains, through which flowed large rivers. It was just such a country as that in which elephants and southern animals would flourish, while vast herds of deer and bovine animals wandered over the entire length and breadth of the land. Where animal life was so abundant there were sure to be carnivorous animals also, and lions, hyenas, tigers, and other animals added to the variety of animal life. This, however, is but one side of the picture. The other presents us with a very different scene; instead of an abundant forest growth, the land supported only dwarf birch, arctic willows, and stunted mosses. Arctic animals, such as musk-sheep and reindeer, lived all the year around in Southern France. The woolly mammoth lived in Spain and Italy. In short, the climate and conditions of life were vastly different in the two stages.