92 USEFUL BIRDS. 



when the tree falls. Lacking the nesting sites, protection, 

 and shelter once aft'ordecl them among the trees, they nmst 

 find other shelter, or perish. The interests of birds and 

 trees are identical, and each must protect the other for the 

 o-ood of all. Birds are conspicuously useful in distributing 

 the seed, and in planting, pruning, and protecting the trees. 



THE FOREST PLANTERS. 

 If we take a white pine cone, containing seeds, break it 

 o})en and examine a seed, we find that it is enveloped in a 

 meml)rane with a wing-like appendage. Now take the seed 

 and toss it into the air, and it will descend to the ground with 

 a rotary motion, like that of a pickerel 

 spoon when drawn through the water. 

 As the seed descends, its wing in rotat- 

 Fig. 30.— The winged seed ing fomis a Spiral plane at an angle with 



of the white pine. ,, t .. £• •v_ n i_ 



the direction of its descent, serving as 

 a parachute to sustain it in the air. If there is the slightest 

 breeze, the seed floats off upon it and descends diagonally 

 to the ground. The phenomenon is much the same as that 

 observed in fiiUinof seeds of the ash and some other deciduous 

 trees. Such seeds are winged, like the pine seed, for dis- 

 tribution. Although they will not float on a gentle breeze, 

 like thistle or dandelion seeds, still, in a strong wind they 

 are carried fifteen or twenty rods, or more. When pine 

 seeds fall to the ground they soon separate from their wings. 

 A heavy washing rain or the foot of some animal may bury 

 them with earth mould, or falling leaves may cover them, 

 and the planting is done. Should they fall upon the surface 

 of a lake, the gentle breeze would waft them along over the 

 surface, like a fleet of little boats, to islands or distant shores ; 

 should they fall upon a stream, they would float away with 

 the current. 



Although the seeds of man}^ forest trees do not grow their 

 own wings, we And them as widely distributed as the seeds 

 of the pine. Notice the distribution of the wild cherry along 

 the roadsides. In spring we see here and there, on bushes 

 or trees, the we])s of the tent caterpillar. They are usually 

 found upon the apple and wild cherry ; and if, late in May, 



