10 
Proceedings of the Royal Society of Edinburgh. [Sess. 
direction of the ice-flow was influenced to some extent by the Baltic basin, 
the movement in that region being westerly and south-westerly. Though 
the ice-field did not extend farther south than the Midlands of England, 
J ames Geikie maintained that the loamy deposits, with characteristic Arctic 
plants in the Hoxne section, indicated an Arctic climate in the south of 
England during this period. They rest upon interglacial fresh-water beds 
with a temperate flora, which are underlain by the chalky boulder clay, 
which he regarded as the Saxonian ground moraine. Palaeolithic man of the 
Mousterian culture stage witnessed the advance of the Polonian ice-sheet, 
and was contemporaneous with the mammoth, woolly rhinoceros, reindeer, 
Arctic fox, and other forms. The glacial conditions evidently led to his 
occupation of the caves of North-West, Central, and Southern Europe. 
The Dtirntenian or Third Interglacial Epoch was characterised by 
temperate conditions, and a forest fauna spread throughout Europe. This 
stage derives its name from the lignite beds at Diirnten in Switzerland, 
which will be referred to in connection with the researches of Penck and 
Bruckner in the Alps. Mousterian man is believed to have existed during 
this period. 
The Mecklenburgian or Fourth Glacial Epoch (Wiirmian of the Alps) 
had certain characteristic features which distinguish it from preceding 
periods of glaciation. The Scandinavian ice was no longer confluent with 
that of Britain. The basin of the Baltic was occupied by an ice-sheet 
which radiated from Scandinavia and Finland, and deposited terminal 
moraines in Denmark and in the northern provinces of Germany and 
Russia. As the ice retreated northwards the land sank to a limited extent, 
the sea advanced, and the Yoldia clays were laid down. 
In North Britain glaciers still occupied the mountain valleys, and, in 
places, reached the sea-level, the land around the Scottish coast being then 
about 100 feet lower than at present. The deposits of the 100 feet beach 
belong to this period. The dominance of Arctic conditions is also indicated 
by the occurrence of Arctic plants in the sediments of some Scottish fresh- 
water lakes, together with the remains of a phyllopod ( Apus glacialis), 
now met with only in Greenland and Spitzbergen. 
The Aurignacian and Solutrean culture stages probably belonged to 
the earlier part of the Fourth Glacial Epoch, and these were followed 
by the Magdalenian, which marked the closing phase of Palaeolithic man 
in Europe. 
At an early stage in his career, James Geikie called attention to the 
evidence of climatic changes, furnished by the later Pleistocene deposits of 
Scotland, which are associated with Neolithic man. He described the 
