SEEDS TRANSPORTED BY WIND. 
55 
Dry weather, the dryer and hotter the better, causes many 
of these stubborn old cones to open their scales and allow 
the seeds to escape. What can be the advantage in cones 
of this nature ? Let us see. A brisk fire passes over the 
ground at irregular intervals, usually of from one to ten 
years ; it licks up all dry leaves and sticks, and kills the 
Fig. 43. — Cone of jack-pine closely 
covering its seeds, often for sev- 
eral years. 
pine trees and all else above ground. The soil and the 
trunks of trees are blackened, and by lack of reflection 
the heat of the sun is rendered more intense ; besides, the 
heat of the fire acts slowly on the unburned cones as they 
are left on the dead trees. By the time the quick hot 
fire has passed over, the cones have slowly opened and 
begun scattering seeds on the vacant and newly burned 
ground, at a time when there is the best possible chance 
for them to grow. I picked a few unopened cones which, 
Fig. 44. — Cone of jack-pine as opened 
by heat, sowing seeds. 
