RECENT GLACIAL WORK IN EUROPE. 105 



land-shells, and its generally unstratified character, owes its ori- 

 gin to rain, frost, and wind. Admitting that some of the loess of 

 the lower grounds may have been reworked by the same agents, 

 Prof. Geikie fonnd no evidence in the facts adduced by German 

 geologists of a " dry-as-dust " epoch having obtained in Europe 

 during any stage of the Pleistocene period. 



Within recent years the fossils of the loess have received close 

 attention, and through them so much knowledge has been gained 

 of the various modifications experienced by Pleistocene organ- 

 isms that, taken with other evidence of interglacial conditions, 

 there is little room to doubt that this period was characterized 

 by great changes of climate. How often arctic, steppe, prairie, 

 and forest faunas and floras have replaced each other is yet a 

 matter of dispute. The occurrence of fossiliferous deposits inter- 

 calated among glacial accumulations throughout all the glaciated 

 tracts of Europe show that however many advances and retreats 

 of the ice there may have been, they were on a gigantic scale 

 characterizing all the glaciated areas. 



The bearing of the establishment of at least two eras of glaci- 

 ation on the position of Palaeolithic man was pointed out by 

 Prof. Geikie. The mere occurrence of glacial deposits under- 

 neath implement-bearing beds no longer proves these latter to be 

 post-glacial. The horizon of glacial accumulations underlying 

 Palaeolithic gravels must now be determined by ascertaining 

 their relative position ; and it is a remarkable fact that the bowl- 

 der-clays which occur beneath such old alluvia belong, without 

 exception, to the earlier stages of the Glacial period. In 1871- , 72 

 Prof. Geikie published a series of papers in the Geological Maga- 

 zine, maintaining that the alluvial and cave deposits must be 

 assigned to preglacial and. interglacial times, and in chief to the 

 latter. Evidence was adduced to show that during the last stage 

 of the Glacial period man lived contemporaneously with a north- 

 ern and Alpine fauna, in such regions as southern France ; and 

 that Palaeolithic man and the southern mammalia never revisited 

 northwestern Europe after extreme glacial conditions had disap- 

 peared. Prof. Geikie at the same time colored a map to show at 

 once the areas covered by the glacial and fluvio-glacial deposits 

 of the last Glacial era, and the districts in which the implement- 

 bearing and ossiferous alluvia had been found ; and this clearly 

 brought out that the latter never occurred at the surface within 

 the regions occupied by the former. Similar evidence has been 

 recently obtained by continental geologists ; and a map published 

 by Dr. Penck in 1884, showing the areas covered by the earlier 

 and later glacial deposits in northern Europe and the Alpine 

 lands, and indicating at the same time the various localities 

 where Palaeolithic finds have occurred, does not give a single 



VOL. XXXVII. 8 



