284 AMERICAN FORESTS. 



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 be effected. 

 We find in the ancient works all that variety of trees which 

 give such unrivalled beauty to our forests, in natural pro- 

 portions. The first growth of 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 will quickly 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 !"* 



We obtain another indication of antiquity in the " garden- 

 beds/' which we have already described. This system of 

 cultivation has long been replaced by the irregular " corn- 

 hills;" and yet, according to Mr. Lapham,-)- the garden-beds 

 are much more recent than some of the mounds, across which 

 they sometimes extend in the same manner as over the 

 adjoining grounds. If, therefore, these mounds belong to the 

 same area as those which are covered with wood, we get thus 

 indications of three periods : the first, that of the mounds 

 themselves ; the second, that of the garden-beds ; and the 

 third, that of the forests. 



But American agriculture was not imported from abroad ; 

 it resulted from, and in return rendered possible, the gradual 

 development of American semi-civilization. This is proved 

 by the fact that the grains of the Old World were entirely 

 absent, and that American agriculture was founded on the 

 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- 



* See also Arch. Amer., vol. i. p. 306. t 1. c. p. 19. 



