584 THE POPULAR SCIENCE MONTHLY. 



ual evolution of human culture. • The lower strata in these great 

 bowls were found to be made up chiefly of mosses and various 

 plants matted together with the trunks of fallen trees, sometimes 

 of very large diameter ; and the botanical examination of the low- 

 est layer of these trees and plants in the various bowls revealed a 

 most important fact : for this layer, the first in point of time, was 

 always of the Scotch fir — which now grows nowhere in the Danish 

 islands, and can not be made to grow anywhere in them — and of 

 plants which are now extinct in these regions, but have retreated 

 within the Arctic Circle. Coming up from the bottom of these 

 great bowls there was found above the first layer a second, in 

 which were matted together masses of oak-trees of different vari- 

 eties ; these, too, were relics of a bygone epoch, since the oak has 

 almost entirely disappeared from Denmark. Above these came a 

 third stratum made up of fallen beech-trees, and the beech is now 

 the most common tree of the Danish Peninsula. 



And now came a second fact of the utmost importance as con- 

 nected with the first : scattered, as a rule, through the lower of 

 these deposits, that of the extinct fir-trees and plants, were found 

 implements and weapons of smooth stone ; in the layer of oak- 

 trees were found implements of bronze ; and among the layer of 

 beeches were found implements and weapons of iron. 



The general result of these investigations in these two sources, 

 the shell mounds and the peat deposits, was the same : the first 

 civilization evidenced in them was marked by the use of stone 

 implements more or less smooth, showing a progress from the 

 earlier rude Stone period made known by the bone caves ; then 

 came a later progress to a higher civilization, marked by the use 

 of bronze implements ; and, finally, a still higher development 

 when iron began to be used. 



The labors of the Danish archaeologists have resulted in the 

 formation of a great museum at Copenhagen, and on the speci- 

 mens they have found, coupled with those of the drift and bone 

 caves, is based the classification between the main periods or divis- 

 ions in the evolution of the human race above referred to. 



It was not merely in Scandinavian lands that these results 

 were reached; substantially the same discoveries were made in 

 Ireland and France, in Sardinia and Portugal, in Japan and in 

 Brazil, in Cuba and in this country ; in fact, as a rule, in nearly 

 every part of the world which was thoroughly examined.* 



* For the general subject, see Hortillet, Le Prehistorique, p. 498, et passim. For exam- 

 ples of the rude stone implements, improving as we go from earlier to later layers in the bone 

 eaves, see Boyd Dawkins, Early Man in Britain, chap, vii, p. 1S6 ; also Quatrefages, Human 

 Species, New York, 1879, pp. 305 et seg. An interesting gleam of light is thrown on the 

 subject in De Baye, Grottes Prehistoriques de la Marne, pp. 31 et seq. ; also Evans, as cited 

 in the previous chapter. For the more recent investigations in the Danish shell-heaps, see 



