Page:Early Man in Britain and His Place in the Tertiary Period.djvu/156

128 water-rats; while among the smaller animals were the common shrew, the musk shrew (now inhabiting the banks of the Volga), and the common mole. Had he entered these forests in the autumn, he would have seen the wild boars eagerly seeking for acorns as they fell from the trees, and overhead squirrels feasting on the cones of the Scotch fir.

These living and extinct species formed the advanced guard of the Asiatic invasion of Europe at the close of the Pleiocene age, as described in the last chapter, which was probably due to the lowering of the temperature, by which animals hitherto living in Asia were driven to the south and west by the increasing cold in the northern regions. Their arrival marks the first phase of the Pleistocene age in Britain. They belong to the following species:—