196 THE HUMAN SIDE OF PLANTS 
In the movements of climbing plants, there are 
many examples of intellectual suggestion and con- 
trol. The Virginia creeper, which in climbing seeks 
to place its tendril feet in dark cracks and cran- 
nies, is one of these. How does the plant separate 
dark from light, a spot where it may cling from a 
space that will not offer foothold, if not by some 
mental action, some form of reasoning? 
A trumpet-vine grew in a corner of a Southern 
garden. Twenty-odd feet from this vine, in the 
centre of the garden, was an old pine stump; but 
the vine in the corner apparently paid no heed to 
its tall neighbour. One day a fire was built about 
the foot of the stump, and all the bark was burned 
from the surface, leaving the dark, smooth-charred 
body standing. Promptly then the trumpet-vine 
sent forth a long trailer, more than twenty feet 
across open ground, to the charred stump, up which 
it climbed. The parent vine formerly had divided 
its attention among many small shoots and trailers, 
but now it gave its entire attention to this single 
trailer, which had found a good position. And 
before long the whole of the blackened surface was 
hidden beneath the leaves and blossoms of the new 
vine. Was it blind instinct that sent out but one 
long trailer, and that one in direct line to the old, 
charred stump? Was it blind instinct telling the 
