308 GENERAL VIEWS ON ARCHEOLOGY. 



We will state here that there are localities where the pine-trees of 

 the exterior zone enter under and are partially covered over by an 

 upper layer of pine-trees in situ belonging to the central bog region. 



Ascending through the series of formations of the exterior zone of 

 the Skovmose, we find that the pine trees gradually disappear and are 

 replaced by oaks, which finally prevail exclusively. Here again the 

 trees are of handsome stature, betokening a vigorous growth, for the 

 trunks often reach a diameter of four feet. It is the Quercus robur 

 sessijiora of Smith, the Winlereiche of the Germans, which is generally 

 thus found in the Skovmose. As for the Quercus pedunculata of 

 Ehrhard, Sommereiclie of the Germans, that Koch and others consider 

 as specifically different from the first, it has not yet been discovered in 

 the lower portions of the Skovmose, whilst it makes its appearance in 

 the upper layer together with the warty birch, the alder, and the filbert 

 tree. (Speaking of these two forms of oak it has been remarked, in 

 Sweden, for instance, that the Quercus robur preferred uncultivated 

 lands, and that it tended of its own accord to disappear and to give 

 place to the peduncled oak when the soil became improved by a pro- 

 longed cultivation that increased the proportion of humus. 



]Sow, the oak is in its turn in a fair way of disappearing from Den- 

 mark. Although it is still found here and there, especially in Jutland, 

 in thinly peopled and uncultivated districts; it is, however, almost 

 exclusively the peduncled oak which is thus met with. But the 

 arborescent vegetation of Denmark produces now, in preference, the 

 beech, (Fagus silvatica,) and that so luxuriantly, that Denmark is 

 deservedly celebrated for its forests of beech, the finest, it is said, in 

 the whole world. 1 The stranger will be struck no less with the beauty 

 of the beech forests, especially on the pleasant shores of the Sound, 

 than with the profound admiration of the Danes for this ornament of 

 their interesting country. 



If the oak has not entirely disappeared from Denmark, the beech 

 has established a footing there a long while ago, as is testified by public 

 opinion, which holds that the forests of beech are of the highest anti- 

 quity in the country. The beech is missing altogether in the Skov- 

 mose, even in their upper parts. We would not be justified in 

 concluding from this that it did not exist in the country, for this par- 

 ticular locality, on the edge of the marshes, was no more suited to it 

 anciently than it would be nowadays. But the presence alluded to of 

 the wood-grouse in the Kjoekkenmoedding proves, that elsewhere also 

 the pine prevailed in the highest antiquity. 



We come then to the conclusion, that there have been three distinct 

 periods of arborescent vegetation in Denmark; a first period of the pine, 

 a second period of the oak, and lastly a third period — still continuing — 

 of the beech. 



What is the cause of these changes, which have evidently not been 

 abrupt, but which have been brought about little by little, without 

 the intervention of anything like a catastrophe or a cataclysm of 

 nature? 



1 See the Memoir of Vaupell on the invasion of the beech in the forests of Denmark. An- 

 nals of the Natural Sciences. Paris, 1857; tome VII., No. 1, 2. 



