That works of different tribes or nations may frequently be found intermingled on areas over which successive waves of population have passed is admitted, but that one part of what is clearly a system is to be attributed to one people and the other part to another people is a hypothesis unworthy of serious consideration. The only possible explanations of the origin, object, or meaning of these singular structures are based, whether confessedly so or not, on the theory that they are of Indian origin. Remove the Indian element from the problem and we are left without even the shadow of an hypothesis. The fact that the effigy mounds were not used as places of sepulture, and that no cemeteries save the burial mounds are found in connection with them, is almost conclusive proof that the two, as a rule, must be attributed to the same people, that they belong to one system. If this conclusion is considered legitimate, it will lend much aid to the study of these works. It is true it is not new, but it has been generally ignored, and hence could not aid in working out results. The following extract from Dr. Lapham's "Antiquities of Wisconsin" will not be considered inappropriate at this point:[13] The ancient works in Wisconsin are mostly at the very places selected by the present Indians for their abodes, thus indicating that the habits, wants, modes of subsistence, &c., of their builders were essentially the same. If the present tribes have no traditions running back as far as the time of Allouez and Marquette, or even to the more recent time of Jonathan Carver, it is not strange that none should exist in regard to the mounds, which must be of much earlier date. It is by considerations of this nature that we are led to the conclusion that the mound-builders of Wisconsin were none others than the ancestors of the present tribes of Indians. There is some evidence of a greater prevalence than at present of prairie or cultivated land in this State at no very remote age. The largest trees are probably not more than five hundred years old, and large tracts of land are now covered with forests of young trees where there are no traces of an antecedent growth. Every year the high winds prostrate great numbers of trees and frequent storms pass through the forest, throwing down nearly everything before them. Trees are left with a portion of the roots still in the ground, so as to keep them alive for several years after their prostration. These "wind-falls" are of frequent occurrence in the depths of the forests and occasion much difficulty in making the public surveys. The straight lines of the sections frequently encounter them.