The Kitchenmiddens, then, reveal the existence of a population now forgotten, which at first lived in an entirely savage state, but afterwards acquired a certain amount of civilisation. From a chronological point of view, however, this information is still very imperfect. The mixture of implements, sometimes almost without form, and sometimes again showing wonderful workmanship, permits of various interpretations, which have in fact been given. It is different with the objects found in the peat-mosses, and especially in those which the Danes call _skovmoses_, that is, _forest mosses_. These formations are found in hollows of irregular form which have been excavated in Quaternary clays, reaching at times a depth of thirty feet or more. The detailed study which Steenstrup especially has made of them led him to distinguish among them the _central region_ or _peat-moss_, and the _exterior region_ or _forest region_. The first is formed by the cavity itself. It is the peat-moss properly so called, formed by the layers of peat which fill the cavity, and have been deposited subsequently to its formation. A meagre vegetation grew upon the surface, which divides this mass of vegetable _débris_ into distinct zones. They are, proceeding downwards:—1st, certain trees, such as the birch, alder, and hazel, etc., mixed with heaths; 2nd, small stunted, but sturdy pines (_Pinus sylvestris_), which had grown upon peat in which mosses of a high organisation, such as the hypnum, were found; 3rd, compact, amorphous peat, the elements of which for a long time it was considered impossible to discover, but in which MM. Steenstrup and Nathorst discovered in 1872 undoubted remains of five species of plants now confined to the Arctic circle, such as, _Salix herbacea_, _S. polaris_, _S. reticulata_, _Betula nana_, _Dryas octopetala_; 4th, a bed of clay evidently resulting from material washed down by rain from the sides of the hollow, when the latter were still bare. The forest region occupies the sides themselves. The trees were there protected from the wind, and extending their roots into a fertile clay they attained a magnificent development. Now we at once meet with a very remarkable fact, the beech tree is not found in the skovmoses. At the present day it is the essential constituent of the Danish forests; it is the national tree, and the most ancient traditions give no suspicion that it has ever been wanting in Denmark. In its place the peat-mosses contain at first nothing but oaks (_Quercus robur sessilifolia_) which disappeared from the country in prehistoric times, and is only found in a few places in Jutland. Then, as we descend deeper into the peat, the oaks give way to pines. In their turn the latter gain the ascendant, and occupy the lowest parts of the peat exclusively.