306 GENERAL VIEWS ON ARCHEOLOGY. 



fell over into the bog, where they were thus preserved and accu- 

 mulated. It was thought at first that this was caused merely by a 

 gust of wind, but a more careful examination of a peat-bog brought to 

 light the Fact that along its whole circumference the trunks were laid 

 more or less regularly towards the centre. Sometimes the Skovmose 

 is so small that the trees cross it from side to side. Often the trunks 

 have accumulated in such numbers that we might imagine them to be 

 artificially and skillfully heaped up and interwoven in such a manner 

 as to pack together the greatest possible number in the smallest space. 

 When the bog is not small enough to be thus encumbered all over, its 

 central portion is occupied by the peat formation properly so called. 

 We have thus to distinguish in the Skovmose an exterior woody zone 

 and an interior or central bog zone. The latter is formed in an iden- 

 tical manner with that of the Lyngmose, for these differ from the 

 Skovmose merely by the absence of the exterior woody belt, which 

 could not be formed on account of the edges being usually too flat and 

 too little inclined in the Lyngmose. There is consequently a gradual 

 transition from the Lyngmose to the Skovmose, and we may consider 

 these latter as Lyngmose that are very contracted and deepened. 



Central Region of the Skovmose. — Its composition is very regu- 

 lar. The foundation of the basin, occupied by the bog, is formed by 

 an argillaceous layer, produced from the wash of the edges of the 

 depression. Next above this comes a horizontal layer of from one and 

 a half to two feet, in extreme cases of three to four feet, in thickness, 

 of amorphous peat, forming a pulp with the water, and in which we 

 can easily discover with the magnifying glass the presence of vegeta- 

 ble substances, but without being able to distinguish their species. In 

 the normal peat-bogs the amorphous peat is very pure and without ad- 

 mixture of extraneous substances. But, according as the waters were 

 charged with mineral matters, there have often been formed in this 

 inferior stratum, siliceous deposits, composed of the shells of infu- 

 sores, or else of deposits of calcareous tufa, or even also layers of an 

 intermixture of the two matters. These deposits are the sediments of 

 which the water clarified itself. Whilst they were settling, the forma- 

 tion of the peaty matter must have been more or less retarded, to 

 recommence again vigorously at a later time, when the waters had 

 become clearer. 



To the amorphous peat succeeds a layer, usually from three to four 

 feet thick, of a peat which it is easy to recognise as being composed of 

 mosses, (Hypnum.) Then there appear sometimes trunks of pine {Pi- 

 mis sylvestris,) which have grown on the spot, and which have some- 

 times formed a forest on the swamp. But these pine trees are stunted, 

 crooked, and with the rings of their growth (Anneaux d' accroissement) 

 so very close together that seventy have been counted in one inch of 

 thickness. We perceive that the locality was not propitious to them, 

 and yet that did not prevent them from living for three or even four 

 centuries. In the large swamps there are found as many as two and 

 three layers one over the other of these pine trunks in situ, with their 

 bases and roots well preserved. 



As the ground became gradually higher and dryer by the growth of 

 the bog, those species of mosses which had first made their appear- 



