306 A N (' 1 K N T M () N' r M E N T S . 



the strongest evidences of" the high antiquity of these works. In an address before 

 the Historical Society of Ohio, he said : 



" The process by which nature restores the forest to its original state, after 

 being once cleared, is extremely slow. The rich lands of the West are, indeed, 

 soon covered again, but the character of the growth is entirely different, and con- 

 tinues so for a long period. In several places upon the Ohio, and upon the farm 

 which I occupy, clearings were made in the first settlement of the country and 

 subsequently abandoned and suffered to grow up. Some of these new forests are 

 now sure of fifty years' growth, but they have made so little progress towards 

 attaining the appearance of the immediately contiguous forest, as to induce any 

 man of reflection to determine that at least ten times fifty years must elapse before 

 their complete assimilation can be effected. We find in the ancient works all that 

 variety of trees which give sucii unrivalled beauty to our forests, in natural pro- 

 portions. The first growth on the same kind of land, once cleared and then 

 abandoned to nature, on the contrary, is nearly homogeneous, often stinted to one 

 or two, at most three kinds of timber. If the ground has been cultivated, the 

 yellow locust w ill thickly spring up ; if not cultivated, the black and white walnut 

 will be the prevailing growth. * * * Of what immense age then must 

 be the works so often referred to, covered as they are by at least the second 

 growth, after the primitive forest state was regained ?" 



It is not undertaken to assign a period for the assimilation here indicated to 

 take place. It must unquestionably, however, be measured by centuries. 



In respect to the extent of territory occupied at one time, or at successive 

 periods, by the race of the mounds, so far as indicated by the occurrence of their 

 monuments, little need be said in addition to the observations presented in the first 

 chapter. It cannot, however, have escaped notice, that the relics found in the 

 mounds, — composed of materials peculiar to places separated as widely as the 

 ranges of the AUeghanies on the east, and the Sierras of Mexico on the west, 

 the waters of the great lakes on the north, and those of the Gulf of Mexico on 

 the south, — denote the contemporaneous existence of communication between 

 these extremes. For we find, side by side in the same mounds, native copper 

 from Lake Superior, mica from the AUeghanies, shells from the Gulf, and obsidian 

 (perhaps porphyry) from Mexico. This fact seems seriously to conflict with the 

 hypothesis of a migration, either northward or southward. Further and more 

 extended investigations and observations may, nevertheless, serve satisfactorily to 

 settle not only this, but other equally interesting questions connected with the 

 extinct race, whose name is lost to tradition itself, and whose very existence is 

 left to the sole and silent attestation of the rude but often imposing monuments 

 which throng the valleys of the West. 



