4 o6 PREHISTORIC EUROPE. 



been considerably milder than it is now. The occurrence of an 

 ancient dug-out canoe in the buried forest-bed of the Tay valley 

 is the only positive and direct evidence we have that man was 

 an occupant of Scotland in early postglacial times — that is to 

 say, in times anterior to the formation of the Carse-clays and the 

 raised-beach of 45-50 feet. It is highly probable, however, that 

 the buried trees which occur at the bottom of some of the 

 deepest and oldest peat-bogs of the inland districts are syn- 

 chronous with those which underlie the Carse-deposits, and 

 human relics, as is well known, have from time to time been 

 found associated with the former. But as trees and peat-forming 

 mosses have been growing and accumulating in Scotland ever 

 since the earliest invasion of the Germanic flora, it must always 

 be extremely difficult to ascertain the exact position in the 

 postglacial series of any particular peat-bed and buried forest. 

 All we can say is simply this, that the lower portions of the 

 thicker peat-bogs, with their included trees, date probably back 

 to early postglacial times, while their upper parts must belong 

 to a later and often to a very recent date indeed. 



