LECTURE XII. 3-37 



walls of these funnel-sliaped pits, frequently above thirty feet 

 in depth, grew, at the time of their formation, trees which sank 

 so gradually that the tops are turned towards the centre of the 

 bog. In the centre of the bog there is generally at the bottom 

 a clay bed, then a stratum of turf, frequently mixed with 

 lime and microscopic plants, above which lies the proper 

 moss-peat. Firs grew sometimes upon these moors, but did not 

 seem to thrive, and were, at a later period, replaced by the 

 common moor-shrubs Vaccinnium oxycoccos and ullginosimn, the 

 Erica tetralix and vulgaris, the birch, elder, and hazel. Around 

 the borders of the bogs, where large trees grew, the forest 

 vegetation presents a remarkable change. There we find firs 

 fPinus sylvestris) of great height, often thi-ee feet in diameter, 

 which are only distinguished from our common firs by a thicker 

 bark. The rings indicate an age of several centuries. This fir 

 no longer grows in Denmark, nor has it existed there within 

 historical times, nor is there any tradition that it was ever known 

 to the inhabitants of Denmark. These firs frequently stood so 

 thick that by falling into the bogs they formed a kind of floor. 



The firs disappeared and were supplanted by oaks fQuercus 

 rohttr sessili flora) ; stately trees, often four feet in diameter; these 

 have also disappeared, or nearly so. In the upper layer of the 

 peat is found the summer oak (Quercus pedanculataj , with the 

 birch, the hazel, and the alder. At present the Danish forests 

 are formed by the common beech, which is not found in the 

 surface of the forest bogs. The presence of the woodcock in the 

 kitchenmiddens proves that the people who formed them lived 

 during the fir-peribd, and that since then the oak vegetation 

 also passed away, the remains of which are found in the forest 

 bogs, and which has been superseded by the beech. Fir-trunks 

 were found worked by the hand of man, and between these trunks 

 flint implements, which establish the parallel with the kitchen- 

 middens, whilst in the turf-moors, which correspond with the 

 oak period, fine bronze tools were found. 



Human bones were neither found in the kitchenmiddens nor 

 in the peat-bogs of the fir-period ; but graves were discovered 

 composed of large stone blocks, in which only stone- and bone- 

 implements were found. The skulls found in these graves are 



