PRACTICAL ARBORICULTURE 87 



stream ; they would sjtnply drop to the ground and spring up in thickets directly 

 beneath the parent tree. But when devoured by birds they are distributed far 

 and wide, the seedlings taking root wherever a tree or rock or fence permits a bird 

 to perch. Thus they are perpetuated and extended to various portions of the globe. 



The aromatic seeds of the juniper or cedar will only germinate under condi- 

 tions of heat and moisture such as are found in the crops of fowls. The shell being 

 too hard for the enclosed germ to open, hence they would fall to the ground and 

 perish for want of moisture but for the birds. 



The wild apple, pear and pulpy fruits are similarly transferred to distant 

 points, thus ensuring the perpetual propagation of such trees. 



The beech, with its savory nuts, as also chestnuts, chinquapin and other small 

 nuts are borne to hiding places for food by birds and squirrels, while an ample 

 share find their way to the ground, forming new forests. 



The cross-bill, with its peculiar mandibles, opens the cones of pine, ex- 

 tracting the seeds, of which it is fond, and distributes many in flight. 



Birds often practice the art of grafting. The mistletoe of Christmastide, 

 living as a parasite upon the branches of large trees, has clusters of small white 

 berries which contain the seed. They are transferred from branch to branch by 

 adhering to the .bill; the bird pecks into the bark to remove the seed, which thus 

 becomes engrafted into the tree. 



Are the birds disturbed in the wood? So also the forest is constantly 

 harassed by enemies which menace its destruction. 



Age and decrepitude are common to trees as to animals ; their existence ter- 

 minates in decay. Were it not for nature's army of birds, aided by their allies 

 the squirrels, many sorts of trees and plants would become extinct. 



Boring insects penetrate the bark and wood, existing upon the sap of grow- 

 ing trees, and unless held in check by hungry birds, multiply rapidly and eventually 

 destroy the forest. 



Destructive bark beetles become so numerous as to completely girdle large 

 numbers of pine trees. They live upon the cambium which forms the connecting 

 tissues of bark and wood ; their burrows encircle the trees and prevent the sap 

 from ascending to support the foliage, which withers and dies. 



Woodpeckers whose instinct excels the marvelous X-rays, discover the beetle 

 beneath several inches of overlying bark, and boring through thrusts in his long 

 tongue, drawing out beetles and larvae. 



In an official report made to the Commissioner of the Land Office of my visit 

 to the Black Hill forests, I stated that in one tree, eight inches in diameter, we 

 counted and estimated 10,000 beetles and larvae. The bark came off in sections, 

 having been entirely separated from the wood by the insects. There were no 

 woodpeckers, and few other birds, while one-third the entire forest was dead. 



Aphides suck the juices from leaves and tender stems. A horde of worms 

 infest the buds, devouring the vital organs of trees. Birds are always on the alert. 

 Hungry they awake at early dawn to breakfast upon these enemies of the forest. 

 Impelled by hunger they continue their labors all day gathering in the flies, 

 mosquitoes, bugs and worms, thus keeping them in subjection. 



One battalion hovers around the conifers in search of beetles ; other scouts 

 seek those enemies which curl the leaves and feed upon the juices ; a regiment is 



