230 TRACES OF ANCIENT AGRICULTURE. 



first place, the largest trees are probably not more than 

 five hundred years old; and large tracts are now covered 

 with "young trees, where there are no traces of antecedent 

 growth." Every year many trees are blown down, and fre- 

 quent storms pass through the forest, throwing down nearly 

 everything before them. Mr. Lapham gives a map of these 

 windfalls in one district ; they are very conspicuous, firstly, 

 because the trees, having a certain quantity of earth en- 

 tangled among their roots, continue to vegetate for several 

 years ; and, secondly, because even when the trees themselves 

 have died and rotted away, the earth so torn up forms little 

 mounds, which are often mistaken by the inexperienced for 

 Indian graves. "From the paucity of these little * tree- 

 mounds/ we infer that no very great antiquity can be as- 

 signed to the dense forests of Wisconsin, for during a long 

 period of time, with no material change of climate, we would 

 expect to find great numbers of these little monuments of 

 ancient storms scattered everywhere over the ground/' 



But there is other more direct evidence of ancient agri- 

 culture. In many places the ground is covered with small 

 mammillary elevations, which are known as Indian corn- 

 hills. " They are without order of arrangement, being scat- 

 tered over the ground with the greatest irregularity. That 

 these hillocks were formed in the manner indicated by their 

 name, is inferred from the present custom of the Indians. 

 The corn is planted in the same spot each successive year, 

 and the soil is gradually brought up to the size of a little hill 

 by the annual additions/'* But Mr. Lapham has also found 

 traces of an earlier and more systematic cultivation. These 

 consist " of low, parallel ridges, as if corn had been planted 

 in drills. They average four feet in width, twenty-five of 

 them having been counted in the space of a hundred feet ; 

 and the depth of the walk between them is about six inches. 

 * Lapham, I.e. p, 19. 



