142 LIFE OF A TREE. 
be sensible of its own weak points. For if it 
leans to one side at all, and thus becomes in any 
way in danger of falling, it immediately puts 
forth a root from that side of its stem, at some 
height from the ground, and this reaching the 
earth grows vigorously, and becomes a firm, 
strong buttress to the tree, so as perfectly to 
avoid the danger. This is nicely represented in 
the accompanying cut. If a human architect 
had been commissioned to prop up the tree, he 
could not probably have managed it better. 
Sometimes trees will actually send a root across 
an abyss or chasm, on the one side of which they 
may happen to be growing. After growing for 
some time they begin to find a lack of food in the 
spot where they are fixed; and, whether by in- 
stinct or not, we cannot tell, but at any rate per- 
ceiving that on the other side of the ravine there 
is a good supply of rich earth, they send out a 
pioneer in the shape of a root, which bridges over 
the gulf, and in the event actually conveys along 
its countless tubes the food it finds on the other 
side, back to the parent tree. Often we may see 
something of the same sort in our strawberry 
beds. When one of the plants grows near the 
