THE PEAT CLISTASE. 



399 



Scotland during the postglacial time. 



Southern Sieeden during the postglacial time. 

 [Chiefly according to von Post, 1909.] 



The climatic periods 

 of Blytt. 



Changes of 

 level. 



Archaeological 

 time. 



General development of 

 vegetation. 



The subatlantic per- 

 iod. Moist and 

 cold. 



Mya time. 



The subboreal period. 

 Warm and dry. 

 The warmest part 

 of the post-glacial 

 time. 



The Atlantic period. 

 Warm and moist. 



The boreal period. 

 Warm and dry. 



The subarctic period. 

 The arctic period. 



(Limnaea 

 time.) 



Litorina time. 



Maximum ex- 

 tent of the 

 Litorina sea. 



Ancylus time. 



Yoldia time. 



Historical time. 

 The Iron Age. 



The Bronze Age. 



The stone cist 

 time. 



The passage 

 grave time. 

 The dolmen 

 time. 



"The first period 

 of the Swedish 

 Stone Age." 



The time of the 

 kitchenmid- 

 dens. (Magle 

 Mose.) 



Northern plants migrate south- 

 wards. 

 I' The postglacial climate deterio- 

 ration." 



Trapa natans is a common plant 

 of the lakes. The wood mea- 

 dows have their maximum ex- 

 tent. 



Picea excelsa immigrates. (In 

 Norrland the tree limits lay 

 about 200 m. higher; Corylus 

 and other southern plants 

 went further towards the 

 north than at present.) 



Wood meadows and pine forests 

 are the characteristic associa- 

 tions of the dry ground. 



Dryas flora. Aquatic vegetation 

 comparatively luxuriant. At 

 the end of this period more 

 temperate plants immigrate. 



