210 LEAVES FROM THE BOOK OF NATURE. 



brought to light by every excavation, not exactly made 

 for nuts. Our own city of New Orleans, it has been 

 recently discovered, is built upon the most magnificent 

 foundation on which city ever rose. It was the boast 

 of Venice, that her marble palaces rested in the waters 

 of the Adriatic on piles of costly wood, which now serve 

 to pay the debts of her degenerate sons, but our Venice 

 has not less than three tiers of gigantic trees beneath it. 

 They all stand upright, one upon another, with their roots 

 spread out as they grew, and the great Sir Charles Lyell 

 expresses his belief that it must have taken at least 

 eighteen hundred years to fill up the chasm, since one 

 tier had to rot away to a level with the bottom of the 

 swamp before the upper tier could grow upon it. 



But there is still another vegetable world buried be- 

 neath our feet. For the trees of so-called primeval forests 

 belonging to a period of hoary antiquity and far surpassing 

 in exuberance the rankest tropical jungles of our day, 

 have not, like modern woods, undergone decay, but are 

 treasured up in subterranean houses. There they were 

 transformed into vast enduring beds of coal, which in these 

 latter ages has become to man the source of light, of 

 heat, and wealth. Almost all of these trees are gigantic 

 fern-trees, such as the world of our day knows no more ; 

 a few are so-called club-mosses of equally vast dimensions. 

 Leaves and twigs rest closely one upon another, but often 

 entire stems are found standing upright, forty to fifty feet 

 high, with all their roots and branches, dread memorials 

 of times beyond the memory of man. 



Thus we may trace the biography of plants through 



