58 WONDERS OF ORGANIC LIFE. 



but not dead, the vital principle languishes, and 

 at length becomes extinct. But the time 

 required for this extinction of vitality differs in 

 different grades of life, and is preserved the 

 longest, as far as "\ve can positively determine, 

 in the seeds of plants. It has been often 

 observed, especially in America, that when a 

 forest is cut down and the boles of the trees 

 burned to the ground, a new forest (unless the 

 ground be immediately cultivated) springs up, 

 consisting of trees and brushwood, differing 

 totally in species or genera from those which 

 had previously grown there. It is a noted fact 

 also, and one which we have ourselves witnessed 

 hundreds of times, and never without interest, 

 that when a bed of superficial clay is thrown up 

 by the spade into mounds, hillocks, or ridges, 

 it becomes rapidly covered by the common 

 coltsfoot, and decorated with yellow blossoms. 

 In both these cases, we believe that when the 

 superficial deposit took place, the seeds, whence 

 those trees, shrubs, or plants, are called forth, 

 were at that time buried, and that they retained 

 their vitality, waiting perhaps for centuries the 

 day of vivification. That we have proof of the 

 possibility of seeds retaining for two thousand 

 years (under peculiar circumstances, not to be 

 comprehended altogether) their vitality, and yet 

 lying dormant during the revolutions of king- 

 doms, the extinction of languages, and the 

 changes of the great seats of civilization, learn- 

 ing, and commerce — has been more than once 

 or twice proved by the germination of grains of 



