234 INDICATION OF FOUR PERIODS. 



maize, an American plant. Thus, therefore, we appear to 

 have indications of four long periods. 



1. That in which, from an original barbarism, the Ameri- 

 can tribes developed a knowledge of agriculture and a power 

 of combination. 



2. That in which for the first time, mounds were erected, 

 and other great works undertaken. 



3. The age of the " garden beds," which occupy some at 

 least of the mounds. Hence it is probable that these par- 

 ticular " garden beds " were not in use until after the 

 mounds had lost their sacred character in the eyes of the 

 occupants of the soil; for it can hardly be supposed that 

 works executed with so much care would be thus desecrated 

 by their builders. 



4. The period in which man relapsed into partial bar- 

 barism ; and the spots which had been first forest, then, 

 perhaps, sacred monuments, and thirdly cultivated ground, 

 relapsed into forest once more. 



But even if we attribute to these changes all the im- 

 portance which has ever been claimed for them, they will not 

 require an antiquity of more than three thousand years. I 

 do not, of course, deny that the period may have been very 

 much greater, but, in my opinion at least, it need not be 

 greater. At the same time there are other observations, 

 which, if they shall eventually prove to be correct, would 

 indicate a very much higher antiquity. 



One of these is an account* by Dr. A. G. Koch of a mas- 

 todon found in Gasconade County, Missouri, which had 

 apparently been stoned to death by the Indians, and then 

 partially consumed by fire. The fire, he says, was evidently 

 "not an accidental one, but, on the contrary, it had been 

 kindled by human agency, and, according to all appearance, 

 with the design of killing the huge creature, which had been 

 * Trans, of the Academy of Science of St. Louis. 1857. P. 61. 



