The Scottish Naturalist. 85 



the borders of the Mediterranean. The physical evidence furnished by the 

 cave-accumulations and river-deposits of the Pleistocene is quite in keeping 

 with the palaeontological testimony. We have proof that these were formed 

 under varying climatic conditions, and that the final phase was one of flooded 

 rivers bearing sea-ward stone-laden ice-rafts, and of vast inundations which 

 succeeded in covering enormous areas with the finely comminuted loam 

 which they held in suspension, thus giving rise to the brick-earths, loams, 

 toss, lehm, and Unions of geologists. In and underneath these flood-deposits 

 relics and remains of man, and the Pleistocene mammalia have again and 

 again been detected. 



As the toss is generally admitted by geologists to belong to the closing 

 stage of the Pleistocene, it becomes of the utmost importance to trace its con- 

 nection with the Ice Age or Glacial Period. Dr Geikie, therefore, presents 

 us with a summary description of the conditions that obtained in Europe 

 during that period, pointing out the former extent of the ancient glacier sys- 

 tems of the Alps and other mountainous districts of Central and Southern 

 Europe, and showing how, during the climax of glacial cold, all Northern 

 Europe was covered by an enormous ice-sheet that flowed south into Saxony. 

 It was the flood-waters, due to the melting of the ice-masses and snow-fields 

 which then attained so great a development in our continent, that gave rise 

 to the toss and similar accumulations. As remains and relics of man occur 

 in and underneath these deposits, it is clear, as foreign geologists indeed 

 have long maintained, that Palaeolithic man was contemporary with the Ice 

 Age. But this Ice Age was not one of continuous arctic rigour. On the 

 contrary, it was interrupted now and again by mild and genial epochs, and 

 Dr Geikie describes a number of the more interesting and important of the 

 interglacial deposits accumulated during those mild intervals. Reviewing 

 the palaeontological evidence supplied by the glacial and interglacial accumu- 

 lations, he shows that the faunas and floras of those accumulations agree in 

 every respect with the faunas and floras of the cave, alluvial, and other deposits 

 of the Pleistocene Period. They are, in short, one and the same ; and the 

 conviction is forced upon us that the glacial and interglacial deposits are the 

 precise geological equivalents of those Pleistocene deposits, the organic remains 

 of which we have already referred to. In summing up the evidence supplied 

 by the Pleistocene, our author demonstrates that the commencement of this 

 period corresponded with that of the earliest glacial epoch, while its close 

 concurred, in like manner, with the disappearance of the last great northern 

 ice-sheet and the final retreat of the glaciers from the low grounds of Switzer- 

 land, &c. Palaeolithic man and the southern and temperate mammals thus 

 occupied North-western Europe during mild and genial interglacial epochs, 

 retreating south when severe climatic conditions supervened, and leaving 

 what are now the temperate regions of our continent to be clothed and 

 peopled with arctic and high-alpine forms. Of course such great secular 

 migrations imply geographical conditions differing considerably from the 

 present, and the probable outline of sea and land in Pleistocene times is dis- 

 cussed at considerable length. Dr Geikie apparently does not think that the 

 evidence is sufficient to prove that man arrived in Europe so early as Miocene 

 times ; but he is disposed to admit that he may have been living in Italy in 

 a late Pliocene Period. The presumption is in favour of the appearance of 

 Palaeolithic man-in North-western Europe before the advent of the earliest 



