s~ 
902 STRATIGRAPHICAL GEOLOGY.  [Boox VL. 
Period. The Ice Age, or Glacial Period may indeed be said still to 
exist in Europe. ‘lhe snow-fields and glaciers have disappeared 
from Britain, France, the Vosges, and the Harz, but they still 
linger among the Pyrenees, remain in larger mass among the Alps, 
and spread over wide areas in northern Scandinavia. This dove- 
tailing or overlapping of geological periods has been the rule from 
the beginning of time, the apparently abrupt transitions in the 
geological record being due to imperfections in the chronicle. __ 
The last of the long series of geological periods may be sub- 
divided into subordinate sections as follows : 
Historic, up to the present time. 
Tron, Bronze, and later Stone. 
Prehistoric { Neolithic. 
Paleolithic. 
The Human Period is above all distinguished by the presence 
and influence of man. It is difficult to determine how far back the 
limit of the period should be placed. The question has often been 
asked whether man was coeval with the Ice Age. To give an 
answer, we must know within what limits the term Ice Age is used, 
and to what particular country or district the question refers. For 
it is evident that even to-day man is contemporary with the Ice 
Age in the Alpine valleys and in Finmark. There can be no doubt 
that he inhabited Europe after the greatest extension of the ice. 
He not improbably migrated with the animals that came from 
warmer climates into this continent during the interglacial intervals. 
But that he remained when the climate again became cold enoug': 
to freeze the rivers and permit an Arctic fauna to roam far south 
into Kurope is proved by the abundance of his flint implements in 
the thick river-gravels, into which they no doubt often fell through 
holes in the ice as he was fishing. 
The proofs of the existence of man in former geological periods 
are not to be sought for in the occurrence of his own bodily remains, 
as in the case of other animals. His bones are indeed now and then 
to be found, but in the vast majority of cases his former presence is 
revealed by the implements he has left behind him, formed of stone, 
metal, or bone. Many years ago the archeologists of Denmark, 
adopting the subdivisions of the Latin poets, classified the early 
traces of man in three great divisions-—the Stone Age, Bronze Age, 
and [ron Age, There can be no doubt that, on the whole, this has 
been the general order of succession in Hurope, where men used 
stone and bone before they had discovered the use of metal, and 
learnt how to obtain bronze before they knew anything of the metal- 
lurgy of iron. Nevertheless, the use of stone long survived the 
introduction of bronze and iron. In fact, in many Huropean coun- 
tries where metal has been known for many centuries, there are 
districts where stone implements are still employed, or where they 
' See for general information Lyell’s Antiquity of Man, Lubbock’s Prehistorie Times, 
Evans’ Ancient Stone Implements, Boyd Dawkins’ Cave Hunting and Karly Man in 
Britain, oe Geilie’s Prehistoric Murope, 
