30 TYPES OF BRITISH PLANTS 
anything can withstand them. A mass of fungus, grow- 
ing in a cellar, has been known to lift a large paving-slab 
from its bed, and plants, sown by the wind in a crevice 
of the wall, have grown and forced the stones farther 
and farther apart. There is one Indian temple which 
has been made unsafe in this way by a fig tree, sprung 
from a seed dropped casually on the roof, which threatens 
the safety of the entire structure. Just as wonderful, in 
its smaller way, is the muscular power, so to speak, 
with which the tender seedling forces on the top of its 
stem upwards through the earth, and drives its root-cap 
ever lower and lower, shouldering the hard earth aside. 
As an illustration of the enormous power of a growing 
part, one may mention the effect of a root as described 
in Kerner and Oliver’s Natural History of Plants. 
“Tn the Tyrol there is a little valley strewn with large 
blocks of stone. On one of these blocks, at a height of 
two metres,* a larch has long ago established itself and 
rooted firmly, so that the strongest of its roots grew 
downwards in a cleft parallel to the direction of the 
mica streaks. By the thickening of this root the crevice 
became widened ; half of the upper block was separated 
from the lower and raised about thirty centimetres.* It 
is estimated that the weight of this raised portion amounts 
to 1,400 kilogrammes,* and the root which was able to 
raise this burden exhibits in its thickest part a diameter 
of only thirty centimetres. Moreover, the burden over- 
come by this larch root is small in comparison with that 
raised by the roots of old trees.” 
It is by recalling how the trunk of a tree grows in 
* Two metres would be equivalent to 2 yards 6 inches ; thirty centi- 
metres to rather Jess than one foot; and 1,400 kilogrammes to about 
3,000 lbs. (Av.). 
