VITALITY OF SEEDS. 
287 
Besides this, although the accounts of the growth of seeds, 
which have lain for ages in the ashy dryness of Egyptian cata¬ 
combs, are to be received with great caution, or, more proba¬ 
bly, to be rejected altogether, yet their vitality seems almost 
imperishable while they remain in the situations in which 
nature deposits them. When a forest old enough to have 
witnessed the mysteries of the Druids is felled, trees of other 
species spring up in its place; and when they, in their turn, 
fall before the axe, sometimes even as soon as they have 
spread their protecting shade over the surface, the germs 
which their predecessors had shed years, perhaps centuries 
before, sprout up, and in due time, if not choked by other 
trees belonging to a later stage in the order of natural succes¬ 
sion, restore again the original wood. In these cases, the 
seeds of the new crop may often have been brought by the 
wind, by birds, by quadrupeds, or by other causes; but, in 
many instances, this explanation is not probable. 
When newly cleared ground is burnt over in the United 
States, the ashes are hardly cold before they are covered with 
a crop of fire weed, a tall herbaceous plant, very seldom seen 
growing under other circumstances, and often not to be found 
for a distance of many miles from the clearing. Its seeds, 
whether the fruit of an ancient vegetation, or newly sown by 
winds or birds require either a quickening by a heat which 
raises to a certain high point the temperature of the stratum 
where they lie buried, or a special pabulum furnished only by 
the combustion of the vegetable remains that cover the ground 
in the woods. Earth brought up from wells or other excava¬ 
tions soon produces a harvest of plants often very unlike those 
of the local flora. 
Moritz Wagner, as quoted by Wittwer,* remarks in his 
description of Mount Ararat: “ A singular phenomenon to 
which my guide drew my attention is the appearance of sev¬ 
eral plants on the earth-heaps left by the last catastrophe [an 
earthquake], which grow nowhere else on the mountain, and 
* PhysiJcalische Geographic , p. 486. 
