288 
VITALITY OF SEEDS. 
had never been observed in this region before. The seeds of 
these plants were probably brought by birds, and found in the 
loose, clayey soil remaining from the streams of mud, the con¬ 
ditions of growth which the other soil of the mountain refused 
them.” This is probable enough, but it is hardly less so that 
the flowing mud brought them up to the influence of air and 
sun, from depths where a previous convulsion had buried them 
ages before. Seeds of small sylvan plants, too deeply buried 
by successive layers of forest foliage and the mould resulting 
from its decomposition to be reached by the plough when the 
trees are gone and the ground brought under cultivation, may, 
if a wiser posterity replants the wood which sheltered their 
parent stems, germinate and grow, after lying for generations 
in a state of suspended animation. 
Darwin says : “ In Staffordshire, on the estate of a relation, 
where I had ample means of investigation, there was a large 
and extremely barren heath, which had never been touched by 
the hand of man, but several hundred acres of exactly the 
same nature had been enclosed twenty-five years previously 
and planted with Scotch fir. The change in the native vege¬ 
tation of the planted part of the heath was most remarkable— 
more than is generally seen in passing from one quite different 
soil to another; not only the proportional numbers of the 
heath plants were wholly changed, but twelve species of plants 
(not counting grasses and sedges) flourished in the plantation 
which could not be found on the heath.” * Had the author 
informed us that these twelve plants belong to a species whose 
seeds enter into the nutriment of the birds which appeared 
with the young wood, we could easily account for their pres¬ 
ence in the soil; but he says distinctly that the birds were of 
insectivorous species, and it therefore seems more probable 
that the seeds had been dej>osited when an ancient forest pro¬ 
tected the growth of the plants which bore them, and that 
they sprang up to new life when a return of favorable con¬ 
ditions awaked them from a sleep of centuries. Darwin 
* Origin of Species, American edition, p. 69. 
