ny Ve eens ete, 
Address of A. R. Wallace at the Glasgow Meeting. 879 
The next example is that of the ancient mounds and earth- 
works of the North American continent, the bearing of which 
is even more significant. Over the greater part of the exten- 
sive Mississippi valley four well-marked classes of these earth- 
works occur. Some are camps, or works of defence, situated 
on bluffs, promontories, or isolated hills; others are vast inclos- 
ures in the plains and lowlands. often of geometric forms, and 
having attached to them roadways or avenues often miles in 
ength; a third are mounds corresponding to our tumuli, often 
seventy to ninety feet high, and some of them covering acres of 
ground; while a fourth group consist of representations of 
various animals modelled in relief on a gigantic scale, and oc- 
curring chiefly in an area somewhat to the north-west of the 
other classes, in the plains of Wisconsin. 
The first class—the camps or fortified inclosures—resemble in 
valley, which seems to have been a fortified town, incloses an 
area of 127 acres, the embankments measuring three miles in 
length, and containing not less than three million cubic feet of 
arth. This area incloses numerous sacrificial mounds and 
symmetrical earth-works in which many interesting relics and 
Works of art have been found. 
f The second class—the sacred inclosures—may be compared 
or extent and arrangement with Avebury or Carnak—but are 
x some respects even more remarkable. One of these, at 
fi to important, the dimensions of some of these geometrical 
ae. id in different parts of the country and seventy miles apart 
th wentical. Now this proves the use, by the builders of 
«Works, of some standard measures of length, while the 
agonal fizures—shows a considerable knowledge of rudimen- 
aig ceomerry, and some means of measuring. angles. The 
ty of drawing such figures on a large scale is much 
